Seems to me this problem is caused by showing (new to 2.53.10) Firefox 68 in the UA string.
Nope. As I posted the crahs is in modules loading code and 2.57 also affected whichs till has the 60 ua.
(With only a 2 second test ...
& aside from an actual crash in some particular module, it does appears the the code being served is affected by the UA, though the "key" to the UA issue looks not to be 60 vs 68, but rather 9 vs 10 (or I'm guessing, more generally 1 vs 2 digits in the last segment of [SeaMonkey] version number.)
So, this crashes:
Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:68.0) Gecko/20100101 Firefox/68.0 SeaMonkey/2.53.11
where this does not:
Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:68.0) Gecko/20100101 Firefox/68.0 SeaMonkey/2.53.9
(Wonder what's going to break once FF, in the not too distant future, hits 100.x.x
.
Fire 750, bring back 250.
Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.1.19) Gecko/20110420 SeaMonkey/2.0.14 Pinball CopyURL+ FetchTextURL FlashGot NoScript