Hi @UnderwoodMarlene-1858 ,
Thank you for posting in this community.
When you see the error "Multiple User Profiles found with propertyName 'SPS-UserPrincipalName' of specified value," it typically means that there are duplicate user profiles in SharePoint with the same User Principal Name (UPN). Use the User Profile Service Application in Central Administration to identify the duplicate profiles. You can search for the user by their UPN to see if there are multiple entries. If you find duplicate profiles, you can remove the incorrect ones using the User Profile Service Application. Be cautious when deleting profiles to avoid losing important data.After making changes, run a full synchronization of the User Profile Service to ensure that all profiles are updated correctly.
I'm glad to hear you solve the problem, if you have any issue about SharePoint, you are welcome to raise a ticket in this forum. I would make a brief summary of this thread:
Current status:
The issue has been solved. Verify that what went wrong must have been with this particular user. The solution is: Deleted the old User Profile entry using Central Admin & now the workflows are running.
You could click the "Accept Answer" button for this summary to close this thread, and this can make it easier for other community member's to see the useful information when reading this thread. Thanks for your understanding!