You can't add a decent length stack trace to an issue without it crashing on save. When I first started using BB this wasn't a problem, I never hit a limit. Then there was a revision where validation was added to the field such that you had to cut it down before saving. This was worse but it still worked. Currently, it lets you put in whatever you like but crashes when you try to save. You get an error if you try to go back into it, so you end up with a zombie issue.
Issue #5156 duplicate