SRT constantly crashing in Premier Pro

Hello... Hoping desperately for advice... I've imported an SRT file into Premier Pro. I now want to edit quite a lot of these subtitles within Premier. Every time I try to, Premier Pro crashes. I've tried changing the frame rate from 1000 to 25, but every time, it reverts back to 1000 and will not save at 25.

In addition, when I try to even watch the subtitles I have imported alongside the media files, it freezes on just one subtitle and they do not change. When I pause the media using space bar, the correct subtitle then comes up. As soon as I press space bar again, the subtitles revert back to the same frozen subtitle and do not change...

I have spent hours trying to resolve this...

nb// The media is over 2 hours long, so there are a lot of subtitles to change.., Even trying to edit the subs with very low res media or just using audio, I still cannot edit them without Premier crashing. Help! Please!