How to Fix Invalid User Authorization Error in Dynamics 365 Upgraded Workflows

Recently, we upgraded a client’s CRM 2011 to Dynamics 365. In CRM 2011 instance, there were some workflows that were using custom workflow activities. However, after the upgrade, we were getting an error in Dynamics 365 saying, “Invalid User Authorization – The user authentication passed to the platform is not valid”.

I was getting this error when I tried to open the workflows that were using the custom workflow steps, and when I tried to activate a draft workflow process.

I did some research on this issue. I couldn’t find the exact cause of this issue, and it turns out I am not the only one affected by this issue. But what I did find was a workaround for this issue. In this blog, I will walk through the steps that helped me to overcome this issue.

1. Create a backup solution of the all the workflows.
2. After the backup solution has been exported, delete the workflows that are using custom workflow activities.
3. Unregister the custom workflow activities that were added during CRM 2011 to Dynamics 365 upgrade.
4. Register those workflow activities again.
5. Import the backup solution of the workflows that was exported earlier (at step 2).

And this is it, but be sure to test the workflows. The solution above is just a workaround, but I am not a 100% sure what causes this error, and how it can be prevented.