Good afternoon and thank you for posting on the Final Fantasy XIV Technical Support Forums.

Do you recall anything updating/changing on your PC that coincides with this (besides the game itself)?

When you reinstall the game, did you also remove the locally-saved data folder (located My Documents > My Games > Final Fantasy XIV)? Try removing this but be sure to make a backup of this just in case it doesn't resolve the issue.

You can try a clean boot. Simply open the task manager and select the 'Start up' tab. Disable everything here and restart the PC. This will make sure that no background processes are interfering with the game. When you star the game again, disable any overlays that may be present.

You may want to double-check that your anti-virus has the appropriate exceptions for for the install folder and the locally-saved data folder.

We hope we can be of assistance in helping you enjoy the exciting world of Final Fantasy XIV!