A teacher tells me that he/she cannot enter the homework notebook. The message «lesson non-exploitable» appears.

If a lesson is not exploitable, it is because it has not been sufficiently specified in EDT. This may be an undistributed complex lesson, or a co-teaching lesson not identified as such. To solve the problem, go to EDT. Verify the date on which modifications were taken into account in the menu Parameters > Daily management > Placement (if needed, by selecting the first week of the year, so that homework notebooks can be entered retroactively). Then, from the list of lessons, reopen the specifications window to select a distribution mode if it's a complex lesson, or right-click and choose Modify > Place in co-teaching.