Comment 3 for bug 829210

I've run into this as well. It seems to be pretty easy to reproduce.

1. On this bug, click 'Subscribe someone else'
2. Type in some random user
3. Click on their name
4. Click once more on 'Select'
5. The error Dustin mentioned gets shown. There is no Oops number given.
6. A moment later, with no activity taken, the error dialog disappears and the bug reloads
7. The subscribee is not subscribed
8. Repeat again from #1; this time it works at step #4.

This bug does need to be included with the critical bugs; even without an Oops # it is a regression.