Strange video stutter and then crash to desk top

Hi all. I've been having this issue where the game seems to stutter at random. By stuttering I mean the frame rate drops to something like 5. It will then stutter for a few moments before crashing to desk top. I don't encounter this issue often, only after hours of play and sometimes not even then.

I've noticed that this problem seems to crop up the most when I'm teleporting away from a busy area, like a city. Or when I'm running around a very crowded area.

I've discovered a sort of work around however: when the game begins to stutter, I immediately alt+tab out of the game and then bring back the FF14 window. This causes the stutter to cease and the game won't crash.

I don't encounter this issue with my other games.

I was wondering if I should reinstall the game because and if so, do I need the product key again, and how would I download it again since it's a digital copy?

My thanks for any help.