I'm getting the following exception:
Mixed mode assembly is built against version ‘v2.0.50727' of the runtime and cannot be loaded in the 4.0 runtime without additional configuration information.
as I was trying to export crystal report from my WPF program...
I have added the following in the app.config already...
<startup useLegacyV2RuntimeActivationPolicy="true">
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/>
</startup>
<runtime>
<NetFx40_LegacySecurityPolicy enabled="true"/>
</runtime>
Any experts can help????
Reference I found: http://www.davidmoore.info/2010/12/17/running-net-2-runtime-applications-under-the-net-4-runtime
This question is related to
.net
visual-studio-2010
.net-4.0
ado.net
crystal-reports
Try to use another config file (not the one from your project) and RESTART Visual Studio:
C:\Program Files (x86)\Microsoft Visual Studio 11.0\Common7\IDE\CommonExtensions\Microsoft\TestWindow\vstest.executionengine.x86.exe.config
(32-bit)
or
C:\Program Files (x86)\Microsoft Visual Studio 11.0\Common7\IDE\CommonExtensions\Microsoft\TestWindow\vstest.executionengine.exe.config
(64-bit)
If the error happens with error column "File" as SGEN, then the fix needs to be in a file sgen.exe.config
, next to sgen.exe
. For example, for VS 2015, create C:\Program Files (x86)\Microsoft SDKs\Windows\v10.0A\bin\NETFX 4.6 Tools\sgen.exe.config
. Minimum file contents: <configuration><startup useLegacyV2RuntimeActivationPolicy="true"/></configuration>
Source: SGEN Mixed mode assembly
Enabling the legacy from app.config didn't work for me. For unknown reasons, my application wasn't activating V2 runtime policy. I found a work around here.
Enabling the legacy from app.config is a recommended approach but in some cases it doesn't work as expected. Use the following code with in your main application to force Legacy V2 policy:
public static class RuntimePolicyHelper
{
public static bool LegacyV2RuntimeEnabledSuccessfully { get; private set; }
static RuntimePolicyHelper()
{
ICLRRuntimeInfo clrRuntimeInfo =
(ICLRRuntimeInfo)RuntimeEnvironment.GetRuntimeInterfaceAsObject(
Guid.Empty,
typeof(ICLRRuntimeInfo).GUID);
try
{
clrRuntimeInfo.BindAsLegacyV2Runtime();
LegacyV2RuntimeEnabledSuccessfully = true;
}
catch (COMException)
{
// This occurs with an HRESULT meaning
// "A different runtime was already bound to the legacy CLR version 2 activation policy."
LegacyV2RuntimeEnabledSuccessfully = false;
}
}
[ComImport]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
[Guid("BD39D1D2-BA2F-486A-89B0-B4B0CB466891")]
private interface ICLRRuntimeInfo
{
void xGetVersionString();
void xGetRuntimeDirectory();
void xIsLoaded();
void xIsLoadable();
void xLoadErrorString();
void xLoadLibrary();
void xGetProcAddress();
void xGetInterface();
void xSetDefaultStartupFlags();
void xGetDefaultStartupFlags();
[MethodImpl(MethodImplOptions.InternalCall, MethodCodeType = MethodCodeType.Runtime)]
void BindAsLegacyV2Runtime();
}
}
The exception clearly identifies some .NET 2.0.50727 component was included in .NET 4.0. In App.config file use this:
<startup useLegacyV2RuntimeActivationPolicy="true" />
It solved my problem
Try to use this exact startup tag in your app.config under configuration node
<startup useLegacyV2RuntimeActivationPolicy="true">
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/>
<requiredRuntime version="v4.0.20506" />
</startup>
For me this was thrown when running unit tests under MSTest
(VS2015). Had to add
<startup useLegacyV2RuntimeActivationPolicy="true">
</startup>
in
C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE\CommonExtensions\Microsoft\TestWindow\TE.ProcessHost.Managed.exe.config
I actually had this identical issue with the inverse solution. I had upgraded a .NET project to .NET 4.0 and then reverted back to .NET 3.5. The app.config in my project continued to have the following which was causing the above error in question:
<startup>
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/>
</startup>
The solution to solve the error for this was to revert it back to the proper 2.0 reference as follows:
<startup>
<supportedRuntime version="v2.0.50727"/>
</startup>
So if a downgrade is producing the above error, you might need to back up the .NET Framework supported version.
Please add attribute useLegacyV2RuntimeActivationPolicy="true" in your applications app.config file.
Old Value
<startup>
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5.1"/>
</startup>
New Value
<startup useLegacyV2RuntimeActivationPolicy="true">
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5.1"/>
</startup>
It will solve your problem.
Source: Stackoverflow.com