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OPC Data Client only works as a 32 bit application

My application worked fine before but now I'm getting an App_Web_OpcLabs.EasyOpcClassicRaw.amd64 error when I try to run it. I can chance the target platform to (x86) but it will not work as a 64-bit application. What happened and how can I fix this?

The problem stems from Microsoft's .NET Framework 4.6. Customers have reported this issue after a Windows updated where the .NET Framework was updated from 4.5 to 4.6. Our developer has been in contact with Microsoft and this issue is being addressed.

There are two options available for customers wishing to run a 64-bit application:

  1. Uninstall Microsoft .NET Framework 4.6 and reinstall 4.5
  2. Add a DWORD 'useLegacyJIT' under the registry key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework with value of 1.**

**This answer does involve making changes to your Registry. This can cause problems if done incorrectly. If you are not comfortable working within your registry please make a back up copy before doing anything or contact our Support Team.