Debug your workflows on .NET 1.1 and 2.0 machines (CRMWorkflowService.exe.config)
This only applies if you have the 1.1 and 2.0 framework installed and your workflow "addin" is built in .NET 1.1.
Create a new file called CRMWorkflowService.exe.config and copy xml below. Copy file to the same directory as that workflow exe
<configuration>
<startup>
<requiredRuntime imageVersion="v1.1.4322" version="v1.1.4322" />
<supportedRuntime version="v1.1.4322" />
</startup>
</configuration