Diễn đàn hỗ trợ Firefox

I am a Salesforce (improveit! 360) user, exclusively browsing with Firefox for over 12 years without any problems. The most recent Firefox update 125.0.2 (64-bit) has caused an issue with my staff calendar. I have reached out to improveit! 360 they are a force.com developer and they will not help, said the error is caused by Firefox interpreting the code. I have figured out a work around to get the calendar to load correctly for a short term solution. Below is a screenshot of the error, any help would be greatly appreciated.

Every time I open Firefox another blank window opens behind the main Firefox pages . I see it when I close Firefox so have to close that too. There is no URL in the window just a blank page.

Hello, I want to get funky looking tabs like this:

https://imgur.com/a/Xbc4Kih

But I can't figure out how to do it. I've tried searching for a way to do this, but everything I find is very old and doesn't work. One thing I keep finding is this: https://github.com/wilfredwee/photon-australis

But that doesn't work for me, it just makes the tabs less tall. I've tried switching to nightly and that didn't do anything so I'm pretty lost. I don't know CSS or anything so I cant do it myself.

If anyone knows how to do this then please tell me!! thx!