I got the same thing creating an issue here - although the issue was actually created

Looks like some kind of DB problem. Not sure.

BTW we have a security flow here - since we are public we should not throw an exception to user... My proposal is to log any Exception errors and show some friendly message to user like "An error has occurred. Please report it to https://github.com/joomla/jissues/."

I rolled back the filter package again. Apparently something after 1.1.2 is screwing things up royally.

My issue on the last two test items I posted, you can't select No Milestone (if you have that option in the sidebar).

you can't select No Milestone

What do you mean? It is the default value.

BTW that i s the same error that was in #579 and was fixed in a3aa0ea. It seems that it was not? :)

I can't submit the item with No Milestone as the selected value. If I change it to a value which has an ID in the milestones table, it works. The 0 is killing it.

We should have placed the code @wilsonge submitted in #581 in the table class as @b2z commented.
Blame the merger ...