Problem with automatic subgroups

[STAVROULA]

Hello everyone,
Although I created years and groups and no subgroups, FET refuses to run to create a schedule because it cannot keep the constraint of least hours per day.
I haven't created any subgroups in the groups of each year.
What is the problem?
 I had created a constraint of least hours per day. I thought that maybe that causes the problem. I tried to erase it ,but t I could not find it.
Please help!

[Liviu Lalescu]

Hello, STAVROULA,

I would need your file to see the problem.

[STAVROULA]

Thank you very much for your swift response.
I will send it tomorrow when I go back to school.
Have a nice evening

[STAVROULA]

I managed to solve the problem, by erasing the number of students for each class. In this way, the automatic subgroups were the same with the groups.