Symptoms

When deploying workflows, I receive an error "Could not load file or assembly SourceCode.WebDesigner.Management, Version=4.0.0.0".
 

Diagnoses

In order to get rid of that error message the file must be copied to the server that would perform the deployment, K2 server would also need to restart.
 

Resolution

The missing DLL SourceCode.WebDesigner.Management.dll file has been sent to the customer. It resolved the issue.