The test didn’t crash. It just didn’t let the Student go on to the next section until the time was up for the current section. The idea is that it replicates the time constraints in the real test. If the Student had waited then the test would have automatically gone on to the next section once the time was up on the current section.
This is a feature we might change because it has confused a few people in the past. Although it’s good in some ways, it might not suit everybody.
You should be able to reassign the test with no problems. I just logged in to your account and reassigned a test that had already been assigned and it worked ok. Please try again and let us know if you have any further issues.