When trying to file bug 189507 I was given a "Internal Server Error" after clicking the "Commit" button at the bottom of the bug report. I tried several times and was presented with the error each time. I then copy and pasted the contents of the bug report into a text editor window and proceed to the advanced bug filing page. I selected the "Red Hat Errata System" product and pasted the contents again. That time it worked. Note, I didn't initially get to the bug reporting page through the advanced bug filing page. Instead I followed a link from John Poelstra ( https://bugzilla.redhat.com/bugzilla/enter_bug.cgi?product=Red%20Hat%20Errata%20System) directly from an IRC conversation. It's possible it was just a transient error that corrected itself, or I suppose it may also be possible that going straight to enter_bug link from IRC bypassed setting some state that the Advanced form normally sets. I have no idea, I'm just guessing. Another interesting data point is the fedora-update system is apparently down right now (according to Matthias who shares a cube with me), so it may be the bugzilla database server isn't working reliably or something.
Strange error indeed. I tried several ways to enter a new bug and also the link you posted exactly and had no trouble. It could have been due to transient error since I have pushed a couple of fixes today to production. Please reopen this if it occurs for you again.