Do a files check from the Config: Config -> Restore Data. It redownloads and installs corrupted files. Just make sure you backup your hotbars and all that just in case. You can do that by copying the character files in the Documents/My Games/Final Fantasy XIV folder: all the FFXIV_CHR folders are your character data like hotbars, glam plates, job swap stuff, etc. You can copy those and place em on your desktop for a while. Generally that's from a corrupted file or files.