Users expect a prompt listing the resources being removed so that they have an option to confirm which they wish delete.
Release : 15.7
Component : CA PPM SAAS APPLICATION
The error is occurs because the system is trying to remove the resources having actuals as well since those resources are not on the selected OBS.
When the error message does not occur (when all the resources to be removed still have no actuals), there is no option to accept or reject which resources this action would remove and this is the expected behavior of the product. Once the Apply button is clicked on the 'Add/Update by OBS' window that comes up, the resources are removed from the team. However, when there is no error, the resources that are removed are listed in the window so you know which resource to expect to no longer be on the Other Work team.
There is a defect logged for the Error 500 message as it does not provide any details on why it is being thrown. When the error message does occur, the list of which resources are removed is not displayed so it gets confusing when they are removed anyway.
The defect number DE54609 is Fixed in 15.9.2