It seems that, since some days ago, we are getting some errors when restoring course role assignments:

Error: could not insert new context level "70", instance "487".

• line 2291 of lib/accesslib.php: call to debugging()
• line 2612 of lib/accesslib.php: call to create_context()
• line 1084 of course/lib.php: call to get_context_instance()
• line 1726 of lib/datalib.php: call to get_fast_modinfo()
• line 1767 of lib/datalib.php: call to get_all_instances_in_courses()
• line 4830 of mod/forum/lib.php: call to get_all_instances_in_course()
• line 4765 of mod/forum/lib.php: call to forum_add_user_default_subscriptions()
• line 3012 of lib/accesslib.php: call to forum_role_assign()
• line 7910 of backup/restorelib.php: call to role_assign()
• line 7779 of backup/restorelib.php: call to restore_write_roleassignments()
• line 7504 of backup/restorelib.php: call to restore_roles_settings()
• line 47 of backup/restore_execute.html: call to restore_execute()
• line 168 of backup/restore.php: call to include_once()

And the error is dropped a bunch of times (4 in my restore) per user.