Common exceptions in Generate Master Schedule are as follows:

ExceptionMeaning
Meetings conflict with course rule
 
The classes cannot be scheduled because a course rule would be violated. For example, if the rule states that Physics Lab and Study Hall must use the same block on different days, but the course records are both set to use every meeting in the assigned pattern, the rule cannot be met.

(To resolve: After you select a pattern on the Restrictions 2 tab of each of the course records, you must select Specific value in the Number of meetings field and enter a number in the field that appears.)
 
No teacher requested
 
On the Resources tab of the course record, 0 is entered as the number of teachers for each class.
 
The meeting occurs in a room that has reached the daily limit for meetings with non-homeroom teachers
 
The teacher cannot be scheduled because, based on other scheduled classes, the number of floating teachers has been met.
 
Teacher conflicts with course rule
 
The teacher is not a resource on both course records.
 
Room conflicts with course rule
 
The room does not allow concurrent classes or is not a resource on both course records.
 
Course has availability restrictions that overlap the meetings
 
The course record has restricted times that conflict with the meetings Generate Master Schedule is trying to use to create meetings.
 
Room has not been scheduled
 
Meetings cannot be scheduled because the room has not been assigned. This exception can occur if you selected the Generate Master Schedule option that instructs the program to schedule meetings only if a room can be scheduled.
 
Teachers have not been scheduled
 
Meetings cannot be scheduled because a teacher has not been assigned. This exception can occur if you selected the Generate Master Schedule option that instructs the program to schedule meetings only if a teacher can be scheduled.
 
Room and teachers have not been scheduled
 
Meetings cannot be scheduled because a room and a teacher have not been assigned. This exception can occur if you selected the Generate Master Schedule option that instructs the program to schedule meetings only if a room and a teacher can be scheduled.
 
Teacher is restricted to a specific room
 
The room has already been assigned, but the teacher cannot be scheduled because he is restricted to a room other than the one scheduled.
 
Meeting would cause teacher to exceed their max meetings per day limit
 
Meetings cannot be scheduled because doing so would cause the teacher to exceed his maximum meetings per day limit as set on the Restrictions 1 tab of the faculty record.
 
Percentage of requests with conflicts exceeds the max percentage allowed
 
Meeting times have been excluded because they exceed the maximum percentage of conflicts defined on the Advanced tab of Generate Master Schedule.

(The checkbox is Exclude meetings where are least [ ] percent of the students requesting the course have an existing conflict.)
 
Each section must be scheduled in a different block
 
Meetings cannot be scheduled because all available blocks have been used and the Restrictions 2 tab of the course record instructs the program to have each section use a different block.

(The checkbox is Each class must use a different block.)
 
Room has availability restrictions that overlap the meeting
 
Meetings have already been scheduled and a room cannot be scheduled because of time restrictions set on the Restrictions tab of the room record.
 
Teacher has availability restrictions that overlap the meeting
 
Meetings have already been scheduled and a teacher cannot be scheduled because of time restrictions set on the Restrictions 2 tab of the faculty/staff record.