How to fix Referenced assembly does not have a strong name error

Question

I ve added a weakly named assembly to my Visual nbsp Studio nbsp 2005 project  which is strongly named   I m now getting the error       Referenced assembly  xxxxxxxx  does not have a strong name    Do I need to sign this third-party assembly

User · Answer

First make sure all nuget packages are at the same version across all projects in your solution. e.g. you dont want one project to reference NLog 4.0.0.0 and another project to reference NLog 4.1.0.0. Then try reinstalling nuget packages with

Update-Package -reinstall

I had 3 3rd party assemblies that were referenced by my assembly A and only 2 were included in References by my assembly B which also referenced A.

The missing reference to the 3rd party assembly was added by the update package command, and the error went away.

User · Answer

I have written a tool to automatically strong-name sign assemblies including ones you do not have the source code for or projects that have been abandoned  It uses many of the techniques described in the answers in a simple way without any of the flaws or drawbacks of existing tools or dated instructions   http   brutaldev com post 2013 10 18 NET-Assembly-Strong-Name-Signer  Hope this helps out anyone that need to sign a third party assembly without having to jump through hoops to get there

User · Answer

Old question  but I m surprised no one has mentioned ilmerge yet  ilmerge is from Microsoft  but not shipped with VS or the SDKs   You can download it from here though   There is also a github repository   You can also install from nuget   PM gt Install-Package ilmerge   To use   ilmerge assembly dll  keyfile key snk  out assembly dll  targetplatform v4 C  Windows Microsoft NET Framework v4 0 30319  ndebug   If needed  You can generate your own keyfile using sn  from VS    sn -k key snk

User · Answer

I was running into this with a ServiceStack dll I had installed with nuget  Turns out there was another set of dlls available that were labeled signed  Not going to be the answer for everyone  but you may just need to check for an existing signed version of your assembly

User · Answer

How to sign an unsigned third-party assembly  Open up Developer Command Prompt for Visual Studio  This tool is available in your Window programs and can be found using the default Windows search  Ensure your prompt has access to the following tools by executing them once  sn ildasm and ilasm Navigate to the folder where your Cool Library dll is located sn    k Cool Library snk to create a new key pair ildasm Cool Library dll  out Cool Library il to disassemble the library move Cool Library dll Cool Library unsigned dll to keep the original library as a back-up ilasm Cool Library il  dll  resource Cool Library res  key Cool Library snk to reassemble the library with a strong name powershell -command  quot  amp    System Reflection AssemblyName   GetAssemblyName  args  FullName  Cool Library dll quot  to get the assembly fully qualified name  You will need this bit if you have to reference the DLL in external configuration files like web config or app config

User · Answer

To avoid this error you could either    Load the assembly dynamically  or Sign the third-party assembly     You will find instructions on signing third-party assemblies in  NET-fu  Signing an Unsigned Assembly  Without Delay Signing     Signing Third-Party Assemblies  The basic principle to sign a thirp-party is to    Disassemble the assembly using ildasm exe and save the intermediate language  IL    ildasm  all  out thirdPartyLib il thirdPartyLib dll   Rebuild and sign the assembly   ilasm  dll  key myKey snk thirdPartyLib il    Fixing Additional References  The above steps work fine unless your third-party assembly  A dll  references another library  B dll  which also has to be signed  You can disassemble  rebuild and sign both A dll and B dll using the commands above  but at runtime  loading of B dll will fail because A dll was originally built with a reference to the unsigned version of B dll    The fix to this issue is to patch the IL file generated in step 1 above  You will need to add the public key token of B dll to the reference  You get this token by calling   sn -Tp B dll    which will give you the following output   Microsoft  R   NET Framework Strong Name Utility  Version 4 0 30319 33440 Copyright  c  Microsoft Corporation   All rights reserved   Public key  hash algorithm  sha1   002400000480000094000000060200000024000052534131000400000100010093d86f6656eed3 b62780466e6ba30fd15d69a3918e4bbd75d3e9ca8baa5641955c86251ce1e5a83857c7f49288eb 4a0093b20aa9c7faae5184770108d9515905ddd82222514921fa81fff2ea565ae0e98cf66d3758 cb8b22c8efd729821518a76427b7ca1c979caa2d78404da3d44592badc194d05bfdd29b9b8120c 78effe92  Public key token is a8a7ed7203d87bc9   The last line contains the public key token  You then have to search the IL of A dll for the reference to B dll and add the token as follows    assembly extern   23000003   MyAssemblyName      publickeytoken    A8 A7 ED 72 03 D8 7B C9                               ver 10 0 0 0

User · Answer

Signing the third party assembly worked for me  http   www codeproject com Tips 341645 Referenced-assembly-does-not-have-a-strong-name EDIT  I ve learned that it s helpful to post steps in case the linked article is no longer valid  All credit goes to Hiren Khirsaria   Run visual studio command prompt and go to directory where your DLL located  For Example my DLL is located in D  hiren Test dll  Now create the IL file using the command below  D  hiren gt  ildasm  all  out Test il Test dll  this command generates the code library   Generate new key to sign your project  D  hiren gt  sn -k mykey snk  Now sign your library using ilasm command  D  hiren gt  ilasm  dll  key mykey snk Test il

User · Answer

Situation  You had project A B C D in solution X Y  Project A  B  C in X Project A  C  D in Y  I need use project C in project A  but later i dont use  In bin Debug project A had C dll    If I compile solution X  all good   in this solution i delete reference A -  C     but in solution Y I get this problem    Solution is delete C dll in project A bin Debug

User · Answer

For me  the problem was a NuGet package without a strong name  The solution was to install StrongNamer from NuGet  which automatically adds a strong name to all referenced assemblies  Just simply having it referenced in the project fixed my issue

User · Answer

I had this issue for an app that was strongly named then had to change it in order to reference a non-strongly named assembly  so I unchecked  Sign the assembly  in the project properties Signing section but it still complained  I figured it had to be an artifact somewhere causing the problem since I did everything else correctly and it was just that  I found and removed the line    assembly  AssemblyKeyFile  yourkeyfilename snk    from its assemblyInfo cs file   Then no build complaints after that

User · Answer

To avoid this error you could either    Load the assembly dynamically  or Sign the third-party assembly     You will find instructions on signing third-party assemblies in  NET-fu  Signing an Unsigned Assembly  Without Delay Signing     Signing Third-Party Assemblies  The basic principle to sign a thirp-party is to    Disassemble the assembly using ildasm exe and save the intermediate language  IL    ildasm  all  out thirdPartyLib il thirdPartyLib dll   Rebuild and sign the assembly   ilasm  dll  key myKey snk thirdPartyLib il    Fixing Additional References  The above steps work fine unless your third-party assembly  A dll  references another library  B dll  which also has to be signed  You can disassemble  rebuild and sign both A dll and B dll using the commands above  but at runtime  loading of B dll will fail because A dll was originally built with a reference to the unsigned version of B dll    The fix to this issue is to patch the IL file generated in step 1 above  You will need to add the public key token of B dll to the reference  You get this token by calling   sn -Tp B dll    which will give you the following output   Microsoft  R   NET Framework Strong Name Utility  Version 4 0 30319 33440 Copyright  c  Microsoft Corporation   All rights reserved   Public key  hash algorithm  sha1   002400000480000094000000060200000024000052534131000400000100010093d86f6656eed3 b62780466e6ba30fd15d69a3918e4bbd75d3e9ca8baa5641955c86251ce1e5a83857c7f49288eb 4a0093b20aa9c7faae5184770108d9515905ddd82222514921fa81fff2ea565ae0e98cf66d3758 cb8b22c8efd729821518a76427b7ca1c979caa2d78404da3d44592badc194d05bfdd29b9b8120c 78effe92  Public key token is a8a7ed7203d87bc9   The last line contains the public key token  You then have to search the IL of A dll for the reference to B dll and add the token as follows    assembly extern   23000003   MyAssemblyName      publickeytoken    A8 A7 ED 72 03 D8 7B C9                               ver 10 0 0 0

User · Answer

I had this issue for an app that was strongly named then had to change it in order to reference a non-strongly named assembly  so I unchecked  Sign the assembly  in the project properties Signing section but it still complained  I figured it had to be an artifact somewhere causing the problem since I did everything else correctly and it was just that  I found and removed the line    assembly  AssemblyKeyFile  yourkeyfilename snk    from its assemblyInfo cs file   Then no build complaints after that

User · Answer

For me my issue was that I had two of the same NuGet Packages installed with different Versions

User · Answer

How to sign an unsigned third-party assembly  Open up Developer Command Prompt for Visual Studio  This tool is available in your Window programs and can be found using the default Windows search  Ensure your prompt has access to the following tools by executing them once  sn ildasm and ilasm Navigate to the folder where your Cool Library dll is located sn    k Cool Library snk to create a new key pair ildasm Cool Library dll  out Cool Library il to disassemble the library move Cool Library dll Cool Library unsigned dll to keep the original library as a back-up ilasm Cool Library il  dll  resource Cool Library res  key Cool Library snk to reassemble the library with a strong name powershell -command  quot  amp    System Reflection AssemblyName   GetAssemblyName  args  FullName  Cool Library dll quot  to get the assembly fully qualified name  You will need this bit if you have to reference the DLL in external configuration files like web config or app config

User · Answer

First make sure all nuget packages are at the same version across all projects in your solution. e.g. you dont want one project to reference NLog 4.0.0.0 and another project to reference NLog 4.1.0.0. Then try reinstalling nuget packages with

Update-Package -reinstall

I had 3 3rd party assemblies that were referenced by my assembly A and only 2 were included in References by my assembly B which also referenced A.

The missing reference to the 3rd party assembly was added by the update package command, and the error went away.

User · Answer

For me my issue was that I had two of the same NuGet Packages installed with different Versions

User · Answer

For me  the problem was a NuGet package without a strong name  The solution was to install StrongNamer from NuGet  which automatically adds a strong name to all referenced assemblies  Just simply having it referenced in the project fixed my issue

User · Answer

Removing the  Sign the assembly  check mark under the  Signing  tab works as  Michal Stefanow said   Add here is the simplest way to sign your own files and or other people s files   You just need to add this line under the  Post-build event command line     C  Program Files  x86  Microsoft SDKs Windows v7 0A bin signtool exe  sign  f    ProjectDir  YourPfxFileNameHere pfx   p YourPfxFilePasswordHere  d  Your software title here   du http   www yourWebsiteHere com  t http   timestamp verisign com scripts timstamp dll  v    BaseOutputPath   TargetFileName     You can sign other people s files or your own files and as many as you want

User · Answer

There is a NuGet package named StrongNamer by Daniel Plaisted that seems to do the trick  Is the simplest solution that I ve found so far  There are also a number of other NuGet packages to fix the strong naming problem such as Brutal Dev StrongNameSigner by Werner van Deventer  but I have not tested that one or any of the others

User · Answer

I have written a tool to automatically strong-name sign assemblies including ones you do not have the source code for or projects that have been abandoned  It uses many of the techniques described in the answers in a simple way without any of the flaws or drawbacks of existing tools or dated instructions   http   brutaldev com post 2013 10 18 NET-Assembly-Strong-Name-Signer  Hope this helps out anyone that need to sign a third party assembly without having to jump through hoops to get there

User · Answer

I was searching for solution to the very same problem and un-ticking  Sign the assembly  option works for me      as you may notice screenshot comes from VS2010 but hopefully it will help someone

User · Answer

You can use unsigned assemblies if your assembly is also unsigned

User · Answer

To avoid this error you could either    Load the assembly dynamically  or Sign the third-party assembly     You will find instructions on signing third-party assemblies in  NET-fu  Signing an Unsigned Assembly  Without Delay Signing     Signing Third-Party Assemblies  The basic principle to sign a thirp-party is to    Disassemble the assembly using ildasm exe and save the intermediate language  IL    ildasm  all  out thirdPartyLib il thirdPartyLib dll   Rebuild and sign the assembly   ilasm  dll  key myKey snk thirdPartyLib il    Fixing Additional References  The above steps work fine unless your third-party assembly  A dll  references another library  B dll  which also has to be signed  You can disassemble  rebuild and sign both A dll and B dll using the commands above  but at runtime  loading of B dll will fail because A dll was originally built with a reference to the unsigned version of B dll    The fix to this issue is to patch the IL file generated in step 1 above  You will need to add the public key token of B dll to the reference  You get this token by calling   sn -Tp B dll    which will give you the following output   Microsoft  R   NET Framework Strong Name Utility  Version 4 0 30319 33440 Copyright  c  Microsoft Corporation   All rights reserved   Public key  hash algorithm  sha1   002400000480000094000000060200000024000052534131000400000100010093d86f6656eed3 b62780466e6ba30fd15d69a3918e4bbd75d3e9ca8baa5641955c86251ce1e5a83857c7f49288eb 4a0093b20aa9c7faae5184770108d9515905ddd82222514921fa81fff2ea565ae0e98cf66d3758 cb8b22c8efd729821518a76427b7ca1c979caa2d78404da3d44592badc194d05bfdd29b9b8120c 78effe92  Public key token is a8a7ed7203d87bc9   The last line contains the public key token  You then have to search the IL of A dll for the reference to B dll and add the token as follows    assembly extern   23000003   MyAssemblyName      publickeytoken    A8 A7 ED 72 03 D8 7B C9                               ver 10 0 0 0

User · Answer

Removing the  Sign the assembly  check mark under the  Signing  tab works as  Michal Stefanow said   Add here is the simplest way to sign your own files and or other people s files   You just need to add this line under the  Post-build event command line     C  Program Files  x86  Microsoft SDKs Windows v7 0A bin signtool exe  sign  f    ProjectDir  YourPfxFileNameHere pfx   p YourPfxFilePasswordHere  d  Your software title here   du http   www yourWebsiteHere com  t http   timestamp verisign com scripts timstamp dll  v    BaseOutputPath   TargetFileName     You can sign other people s files or your own files and as many as you want

User · Answer

I was running into this with a ServiceStack dll I had installed with nuget  Turns out there was another set of dlls available that were labeled signed  Not going to be the answer for everyone  but you may just need to check for an existing signed version of your assembly

User · Answer

I was searching for solution to the very same problem and un-ticking  Sign the assembly  option works for me      as you may notice screenshot comes from VS2010 but hopefully it will help someone

User · Answer

There is a NuGet package named StrongNamer by Daniel Plaisted that seems to do the trick  Is the simplest solution that I ve found so far  There are also a number of other NuGet packages to fix the strong naming problem such as Brutal Dev StrongNameSigner by Werner van Deventer  but I have not tested that one or any of the others

User · Answer

Situation  You had project A B C D in solution X Y  Project A  B  C in X Project A  C  D in Y  I need use project C in project A  but later i dont use  In bin Debug project A had C dll    If I compile solution X  all good   in this solution i delete reference A -  C     but in solution Y I get this problem    Solution is delete C dll in project A bin Debug

User · Answer

Expand the project file that is using the project that does not  have a strong name key  and look for the  snk file   StrongNameKey    Browse through to this file in Windows nbsp Explorer  just so that you know where it is    Back in Visual Studio in the project that does not  have a strong name key   do   Right click on the project file Select Properties Select  Signing tab   on the left  Click the check box  Sign the assembly  Then  lt Browse gt  to the  snk file you found earlier   That should do the trick  This solved a problem for me for one project using a form inside another project in the same solution   I hope it helps

User · Answer

Expand the project file that is using the project that does not  have a strong name key  and look for the  snk file   StrongNameKey    Browse through to this file in Windows nbsp Explorer  just so that you know where it is    Back in Visual Studio in the project that does not  have a strong name key   do   Right click on the project file Select Properties Select  Signing tab   on the left  Click the check box  Sign the assembly  Then  lt Browse gt  to the  snk file you found earlier   That should do the trick  This solved a problem for me for one project using a form inside another project in the same solution   I hope it helps

User · Answer

To avoid this error you could either    Load the assembly dynamically  or Sign the third-party assembly     You will find instructions on signing third-party assemblies in  NET-fu  Signing an Unsigned Assembly  Without Delay Signing     Signing Third-Party Assemblies  The basic principle to sign a thirp-party is to    Disassemble the assembly using ildasm exe and save the intermediate language  IL    ildasm  all  out thirdPartyLib il thirdPartyLib dll   Rebuild and sign the assembly   ilasm  dll  key myKey snk thirdPartyLib il    Fixing Additional References  The above steps work fine unless your third-party assembly  A dll  references another library  B dll  which also has to be signed  You can disassemble  rebuild and sign both A dll and B dll using the commands above  but at runtime  loading of B dll will fail because A dll was originally built with a reference to the unsigned version of B dll    The fix to this issue is to patch the IL file generated in step 1 above  You will need to add the public key token of B dll to the reference  You get this token by calling   sn -Tp B dll    which will give you the following output   Microsoft  R   NET Framework Strong Name Utility  Version 4 0 30319 33440 Copyright  c  Microsoft Corporation   All rights reserved   Public key  hash algorithm  sha1   002400000480000094000000060200000024000052534131000400000100010093d86f6656eed3 b62780466e6ba30fd15d69a3918e4bbd75d3e9ca8baa5641955c86251ce1e5a83857c7f49288eb 4a0093b20aa9c7faae5184770108d9515905ddd82222514921fa81fff2ea565ae0e98cf66d3758 cb8b22c8efd729821518a76427b7ca1c979caa2d78404da3d44592badc194d05bfdd29b9b8120c 78effe92  Public key token is a8a7ed7203d87bc9   The last line contains the public key token  You then have to search the IL of A dll for the reference to B dll and add the token as follows    assembly extern   23000003   MyAssemblyName      publickeytoken    A8 A7 ED 72 03 D8 7B C9                               ver 10 0 0 0

User · Answer

Signing the third party assembly worked for me  http   www codeproject com Tips 341645 Referenced-assembly-does-not-have-a-strong-name EDIT  I ve learned that it s helpful to post steps in case the linked article is no longer valid  All credit goes to Hiren Khirsaria   Run visual studio command prompt and go to directory where your DLL located  For Example my DLL is located in D  hiren Test dll  Now create the IL file using the command below  D  hiren gt  ildasm  all  out Test il Test dll  this command generates the code library   Generate new key to sign your project  D  hiren gt  sn -k mykey snk  Now sign your library using ilasm command  D  hiren gt  ilasm  dll  key mykey snk Test il

User · Answer

Old question  but I m surprised no one has mentioned ilmerge yet  ilmerge is from Microsoft  but not shipped with VS or the SDKs   You can download it from here though   There is also a github repository   You can also install from nuget   PM gt Install-Package ilmerge   To use   ilmerge assembly dll  keyfile key snk  out assembly dll  targetplatform v4 C  Windows Microsoft NET Framework v4 0 30319  ndebug   If needed  You can generate your own keyfile using sn  from VS    sn -k key snk

User · Answer

You can use unsigned assemblies if your assembly is also unsigned

[c#] How to fix "Referenced assembly does not have a strong name" error?

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