Summary

When configuring a Route Entry to Group or Route Entry to User activity, you may receive the following error message when specifying a trustee:

System.Exception: Unexpected error: 'WorkflowUserService'. Value cannot be null

Resolution

In the Workflow Designer, make sure there is a valid trustee provider configuration.

To check trustee provider configuration

1. Load the Workflow Designer.
2. From the Tools menu, click Trustee Provider Configuration.