>>>For me, Firefox 115.0.2 (64-bit) on Windows 10 64-bit is tab-crashing on this site. Basically, whenever any action tries to load content in the top right pane/treeview.
>>>MS Edge is not affected, so no doubt it's a bug in Firefox.
>>>Firefox has good automatic error reporting functions, so I imagine they already have multiple bug reports.
>>>
>>
>>Just for another data point, I'm on Win10 64 with that version of Firefox and having no trouble.
>
>I did see a few tab crashes with other sites later yesterday. So far, all sites are working normally for me today.
>
>I run the NoScript security add-on, with this site allowed. I see that NoScript's most recent auto-update was yesterday, July 26th. Maybe there was a problem with that add-on.

Firefox had a change of heart a few years ago and completely changed the API for add-ons, citing security as the reason (and also not keeping two APIs). Lots of add-on stuff just suddenly stopped working, and the work of hundreds of programmers was thrown out.

As it happens in the open source world, some disagreed and... ever since then I'm using https://www.waterfox.net/ - a different branch which feels like Firefox should, and it just works.