Attempted to read or write protected memory This is often an indication that other memory is corrupt

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I m hoping someone can enlighten me as to what could possibly be causing this error      Attempted to read or write protected memory  This is often an indication that other memory is corrupt    I cannot really post code because this error seems to get thrown in any random area of the application  The application will run anywhere from 12-48 hours before throwing the error  Sometimes it will stop in a seemingly random spot and throw the above error  other times the entire application stops and I get a screen with an error that says something along the lines of  There was a fatal error in    This may be a bug in the CLR or     something about PInvoke or other non relevant info  When this happens all threads show terminated and there is no debugging information available    In a nutshell this is what the application does   Its a multi-threaded server application written in entirely in C   Clients connect to the server via socket  The server runs a virtual  environment  for the clients where they can interact with each other and the environment  It consumes quite a bit of memory but I do not see it leaking  It typically consumes about 1 5GB   I dont think its leaking because the memory usage stays relatively constant the entire time the application is running  Its constantly running code to maintain the environment even if the clients are not doing anything  It uses no 3rd party software or other APIs  The only outside resources this application uses is socket connections and SQL database connections  Its running on a 64bit server  I have tried debugging this in VS2008  amp  VS2010 using  net 2 0  3 5  and 4 0 and on multiple servers and the problem still eventually occurs    I ve tried turning off compiler optimizations and several microsoft hot-fixes  Nothing seems to make this issue go away  It would be appreciated if anyone knows any possible causes  or some kind of way to identify whats causing the problem

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This happened to me when I was debugging my C# WinForms application in Visual Studio. My application makes calls to Win32 stuff via DllImport, e.g.

[DllImport("Secur32.dll", SetLastError = false)]
private static extern uint LsaEnumerateLogonSessions(out UInt64 LogonSessionCount, out IntPtr LogonSessionList);

Running Visual Studio "as Administrator" solved the problem for me.

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I also faced this issue with Visual Studio VS  2010  More interestingly  I had several projects in my solution  Console application  WPF application  Windows Forms application  but it was failing only when  I was setting the  Console Application  type of project as start up project of the solution Even for those which had literally no code or any additional assemblies referred apart from the default ones which come with project template itself      Following change finally helped me nail down the issue  Go to project properties of the console application project  Alternatively  select project file in solution explorer and press Alt   Enter key combination  -  Go to Debug tab -  Scroll to Enable Debuggers section in right pane -  Check the Enable unmanaged code debugging check box as shown in the snapshot below -  Click Floppy button in the toolbar to save project properties  Root cause of why it happened is still not known to me  Only thing I observed was that there were lot of windows updates which had got installed on my machine the previous night which mostly constituted of office updates and OS updates  More than a dozen KB articles      Update  VS 2017 onward the setting name has changed as shown in the screenshot below

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In my case I had to reference a C C   library using P Invoke  but I had to ensure that the memory was allocated for the output array first using fixed    DllImport  my c func lib dll   CharSet   CharSet Ansi   public static extern unsafe int my c func double input1  double input2  double pinput3  double  outData        public unsafe double   GetMyUnmanagedCodeValue double input1  double input2  double input3                double   outData   new double 24            fixed  double  returnValue   outData                        my c func input1  input2  pinput3  returnValue                      return outData          For details please see   https   www c-sharpcorner com article pointers-in-C-Sharp

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I faced the same issue  My code was a  NET dll  AutoCAD extension  running inside AutoCAD 2012  I am also using Oracle DataAccess and my code was throwing the same exception during ExecuteNonQuery    I luckily solved this problem by changing the  net version of the ODP I was using  that is  2 x of Oracle DataAccess

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Try to run this command     netsh winsock reset   Source  https   stackoverflow com a 20492181 1057791

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It could be hardware  It could be something complicated   but I d take a stab at suggesting that somewhere your threading code is not protecting some collection  such as a dictionary  with an appropriate lock   What OS and service pack are you running

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I got this error when using pinvoke on a method that takes a reference to a StringBuilder  I had used the default constructor which apparently only allocates 16 bytes  Windows tried to put more than 16 bytes in the buffer and caused a buffer overrun   Instead of  StringBuilder windowText   new StringBuilder       Probable overflow of default capacity  16    Use a larger capacity   StringBuilder windowText   new StringBuilder 3000

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Finally tracked this down with the help of WinDBG and SOS   Access violation was being thrown by some unknown DLL  Turns out a piece of software called  Nvidia Network Manager  was causing the problems  I d read countless times how this issue can be caused by firewalls or antivirus  neither of which I am using so I dismissed this idea  Also  I was under the assumption that it was not environmental because it occurs on more than 1 server using different hardware  Turns out all the machines I tested this on were running  NVidia Network Manager   I believe it installs with the rest of the motherboard drivers     Hopefully this helps someone as this issue was plaguing my application for a very long time

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Got this error randomly in VS1017  when trying to build a project that was building perfectly fine the day before   Restarting the PC fixed the issue worked  I also ran the following command beforehand  not sure if it s required  netsh winsock reset

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Verifiable code should not be able to corrupt memory  so there s something unsafe going on   Are you using any unsafe code anywhere  such as in buffer processing   Also  the stuff about PInvoke may not be irrelevant  as PInvoke involves a transition to unmanaged code and associated marshaling   My best recommendation is to attach to a crashed instance and use WinDBG and SOS to dig deeper into what s happening at the time of the crash   This is not for the faint of heart  but at this point you may need to break out more powerful tools to determine what  exactly  is going wrong

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This may not be the best answer for the above question  but the problem of mine was invalid dispose syntax and usage of lock this  for a buffer object  It turned out the object was getting disposed from another thread because of  quot using quot  syntax  And the processing lock   was on a loose type     wrong lock syntax lock this           modify buffer object    I changed the locks to private static readonly object  lockObject   new object     lock  lockObject           modify buffer object    And used suggested C  disposing syntax and the problem gone      public void Dispose                 Dispose true           GC SuppressFinalize this              protected virtual void Dispose bool disposing                if  disposed              return           if  disposing                           Free any managed objects here             buffer  Free                       disposed   true

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I got the same error in a project I was working with in VB NET  Checking the  Enable application framework  on the properties page solved it for me

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I ve ran into  and found a resolution to this exception today  It was occurring when I was trying to debug a unit test  NUnit  that called a virtual method on an abstract class   The issue appears to be with the  NET 4 5 1 install   I have downloaded  NET 4 5 2 and installed  my projects still reference  NET 4 5 1  and the issue is resolved   Source of solution    https   connect microsoft com VisualStudio feedback details 819552 visual-studio-debugger-throws-accessviolationexception

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My answer very much depends on your scenario but we had an issue trying to upgrade a  NET application for a client which was   10 years old so they could make it work on Windows 8 1   alhazen s answer was kind of in the correct ballpark for me  The application was relying on a third-party DLL the client didn t want to pay to update  Pegasus Accusoft ImagXpress   We re-targeted the application for  NET 4 5 but each time the following line executed we received the AccessViolationException was unhandled message   UnlockPICImagXpress PS Unlock  1908228217 373714400 1341834561 28447     To fix it  we had to add the following post-build event to the project   call    DevEnvDir    tools vsvars32 bat   C  Program Files  x86  Microsoft Visual Studio 11 0 VC bin amd64 editbin exe   NXCOMPAT NO    TargetPath     This explicitly specifies the executable as incompatible with Data Execution Prevention  For more details see here

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I had this problem recently when I changed the development server for a project  I was getting this error on the line of code where I declared a new OracleConnection variable   After trying many things  including installing hotfixes  I tried changing the references Oracle DataAccess and System Data OracleClient in the project and it worked   When a project is moved to a new machine  I suggest you renew all the references added in that project

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i had this problem too   i was running different solutions at the same time using visual studio   when closing other solutions and running just the target solution   it worked fine without that error

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Did you try turning off DEP  Data Execution Prevention  for your application

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I have just faced this issue in VS 2013  NET 4 5 with a MapInfo DLL  Turns out  the problem was that I changed the Platform for Build from x86 to Any CPU and that was enough to trigger this error  Changing it back to x86 did the trick  Might help someone

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The problem may be due to mixed build platforms DLLs in the project  i e You build your project to Any CPU but have some DLLs in the project already built for x86 platform  These will cause random crashes because of different memory mapping of 32bit and 64bit architecture  If all the DLLs are built for one platform the problem can be solved

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I got this error message on lambda expression that was using Linq to filter a collection of objects  When I inspected the collection I noticed that its members weren t populated - in the Locals window  expanding them just showed  quot     quot   Ultimately the problem was in the repository method that initially populated the collection - Dapper was trying to automatically map a property of a nested object  I fixed the Dapper query to handle the multi-mapping and that fixed the memory error

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This error should not happen in the managed code  This might solve the issue   Go to Visual Studio Debugger to bypass this exception   Tools menu - gt Options - gt  Debugging - gt  General - gt  Uncheck this option  Suppress JIT optimization on module load    Hope it will help

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in my case the file was open and therefore locked    I was getting it when trying to load an Excel file using LinqToExcel that was also opened in Excel    this is all I deeded      var maps   from f in book Worksheet lt NavMapping gt                    select f      try           foreach  var m in maps              if   string IsNullOrEmpty m SSS ID   amp  amp   mappings ContainsKey m SSS ID                    mappings Add m SSS ID  m CDS ID         catch  AccessViolationException ex             logger Error  mapping file error  most likely this file is locked or open      ex

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In my case the FTDI utility FT Prog was throwing the error as it scanned for USB devices  Unplugging my Bluetooth headphones from the PC fixed the issue

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Ok  this could be pretty useless and simply anecdotal  but     This exception was thrown consistently by some Twain32 libraries we were using in my project  but would only happen in my machine   I tried lots of suggested solutions all over the internet  to no avail    Until I unplugged my cellphone  it was connected through the USB    And it worked   Turns out the Twain32 libraries were trying to list my phone as a Twain compatible device  and something it did in that process caused that exception   Go figure

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I had the same error message      System AccessViolationException  Attempted to read or write protected memory  This is often an indication that other memory is corrupt    In my case  the error went away after clean and re-build the solution

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This issue is almost invariably a simple one  The code is bad  It s rarely the tools  just from a statistical analysis  Untold millions of people are using Visual Studio every day and maybe a few are using your code - which bit of code is getting the better testing  I guarantee that  if this were a problem with VS  we would probably already have found it   What the statement means is that  when you try to access memory that isn t yours  it s usually because you re doing it with a corrupted pointer  that came from somewhere else  That s why it s stating the indication   With memory corruption  the catching of the error is rarely near the root cause of the error  And the effects are exactly what you describe  seemingly random  You ll just have to look at the usual culprits  things like    uninitialised pointers or other values  writing more to a buffer than its size  resources shared by threads that aren t protected by mutexes    Working backwards from a problem like this to find the root cause is incredibly difficult given that so much could have happened between the creation of the problem and the detection of the problem   I mostly find it s easier to have a look at what is corrupt  say  a specific pointer  and then do manual static analysis of the code to see what could have corrupted it  checking for the usual culprits as shown above  However  even this won t catch long chains of problems   I m not familiar enough with VS to know but you may also want to look into the possibility of using a memory tracking tool  like valgrind for Linux  to see if it can spot any obvious issues

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In some cases  this might happen when   obj   new obj        obj Dispose         lt -----------------    Incorrect disposal causes it obj abc

[c#] Attempted to read or write protected memory. This is often an indication that other memory is corrupt

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