I'm not sure why this is happening as it's never happened to me until 5.5's installation - but every time I try to really do anything or even just launch the game I get a near instant fatal dx11 crash.

Usually looks something like this (copied from the most recent crash report):

~~

An unexpected error has occurred. Exiting FINAL FANTASY XIV.

ffxiv_dx11.exe+139F617
ffxiv_dx11.exe+131C6F9
ffxiv_dx11.exe+4680BC
ffxiv_dx11.exe+197382
ffxiv_dx11.exe+13E5CE9
KERNEL32.DLL+17034
ntdll.dll+52651

~~

I'm really not sure what to do here and I'd rather not have to reinstall, but I would like some help.