RegAsm failing for a .NET 4.0 assembly using Microsoft.Bcl.Async

Question

RegAsm failing for a .NET 4.0 assembly using Microsoft.Bcl.Async with the following message:

RegAsm : error RA0000 : Could not load file or assembly          


        

Answer 1

The solution I have come up with is a hack:

• copied RegAsm.exe and RegAsm.exe.config from C:\Windows\Microsoft.NET\Framework\v4.0.30319\RegAsm.exe to a local folder where MyAssembly.dll is;

• edited RegAsm.exe.config to look like this:

<?xml version ="1.0"?>
<configuration>
    <startup useLegacyV2RuntimeActivationPolicy="true">
        <requiredRuntime safemode="true" imageVersion="v4.0.30319" version="v4.0.30319"/>
        <supportedRuntime version="v4.0" sku="client" />
    </startup>

  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <assemblyIdentity name="System.IO" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-2.6.6.0" newVersion="2.6.6.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Runtime" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-2.6.6.0" newVersion="2.6.6.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Threading.Tasks" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-2.6.6.0" newVersion="2.6.6.0" />
      </dependentAssembly>
    </assemblyBinding>
  </runtime>

</configuration>

• now, running RegAsm.exe /codebase MyAssembly.dll works fine as expected.

Interestingly, useLegacyV2RuntimeActivationPolicy="true" has already been there in the standard RegAsm.exe.config, but alone it did not help.

I think this is the same bug reported here: https://connect.microsoft.com/VisualStudio/feedback/details/789318/asyncpack-system-io-fileloadexception-could-not-load-file-or-assembly-system-threading-tasks-version-1-5-11-0.