simultaneous activites (request determind indirectly)

[Sue Moran]

My timetable is struggling to generate I tried to help it along by adding some time constraints to get some activites timetabled at the same time. I thought that would work but now I have this message. The activites.. and ... must be simultaneous (request determind indirectly) but they have common teachers...etc
These activites I haven't requested and are impossible, how are they determind indirectly? Any ideas?? Thanks for your time.

[Volker Dirr]

I don't understand the whole problem. Please ask more detailed.