We have a managed solution that has deployed without errors to two CRM instances but has failed on the most critical system.
EntityRelationship [<customentity>_ActivityPointers] is invalid. The lookup attribute [RegardingObjectId] is already associated with an existing relationship.
When we check the target instance there is no releationship present between these two entities prior to deployment, so we have confirmed that is not a mix up in releationship names.
The primary difference between this solution and the previous working deployment is that we have checked the box under "Communication and Collaboration" for Activities on our custom entity.
We have also confirmed that this flag is not currently checked for this custom entity on the target instance.
Has anyone experienced similar issues and how did they recover the situation so that the solution can be deployed?
The solution has been redeployed to the other CRM instances subsequently and they do not report any issues.