Launcher Script Error "Invalid character"

[worldofneil]

I keep seeing threads about adjusting IE settings but Microsoft Edge doesn't have any of the settings I am meant to change, at least not readily.

Because Edge is not Internet Explorer

Microsoft might want people to use Edge, but Internet Explorer still exists as a completely separate browser (which is also the Windows default browser which in turn is what the Final Fantasy XIV launcher uses).

So don't load Edge, instead actually load Internet Explorer then you'll find the options you're looking for

(and once you delete the Temporary Internet Files in IE (the cache) it'll likely fix your launcher issue)