I am using Visual Studio 2017 (15.9.8) with an on-premise installation of TFS 2017. In our team a checkin is required to have some associated work item. This worked fine and does still with all of my colleagues. But when I do a checkin, I get the error message (see title) with every work item I associate. Since checkin works fine, it is just annoying to associate the change sets manually.
I do not use any custom code, so I can't debug any API (as suggested by Shayki Abramczyk) - it's just a matter between VS and TFS. I tried to intercept the communication between VS and TFS, but that did not work yet.
How can I find out which fields are invalid? Is there any type of log where I can research the cause?
Guenter