1. Unable to test due to lack of communication with partner group.

2. Too many groups trying to test on robot at same time- cannot test on robot.

3. Requirements change necessitates changes to other aspects of system.

4. Unable to incorporate debugger into modified system.

5. Confuse different versions of the software.

6. Other group did not finish work.

7. Permission problems with directories/files.

8. Server crashes.

9. Adding functionality could affect the rest of the system.

10. Only some group members fully understand software.