Choice Activity - More students signing up than the limit set

The problem exists when 'separate groups' or visible groups' are set in the common module settings for the activity. This effectively multiplies the response limit by the number of groups and extends the maximum limit.

To avoid this happening for future activities the common module settings should be set to 'no groups' which leaves the pool of students as one and the limit you have set will apply.

It might also be worth considering using the Group Selection activity for these types of allocations in future.