Assembly must be registered in isolation – Dynamics 365 On Premise

Hi Everyone,

Today I was working on on-premise system after so many years and as per the requirement I need to update the one of the step from Async to Sync and when I tried doing that, was continuously getting error saying “Assembly must be registered in isolation.”

Later I found that that Assembly was registered in “None” mode (Not in Sandbox mode) and the User with which I am trying to update the step doesn’t have Deployment Administrator Role.

After adding the User to the Deployment Administrator role via Deployment Manager, I was able to update the step.

Hope this helps.


Happy 365’ing
Gopinath.