Possible solution for Error 11018 (File access failed during version check)
Most of the information you find on google does not really help, so I am posting a solution that worked for me.
If you get this error message:
"File access failed during version check. [11018]"
That means the launcher (ffxivboot.exe) can't access your 'My Documents' folder.
There can be many reasons for this, for example an over protective anti virus\anti adware or a similar program that blocks access to your user folder. (usually C:\Users\{YourUserName]\)
Another possible reason is that you or your Windows somehow screwed up your 'My Documents' folder.
The reason for this might be a change in your hard disk setup (installing an SSD, connecting a USB hard drive that has a different 'My Documents' folder on it). In my case, Windows had changed the folder's location to a path on my USB hard drive.
To repair the folder, you have to search your registry (Windows key + R, regedit, enter) for
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders
in both of these folders, look for the key "Personal",
now type in your preferred folder location (usually C:\Users\{YourUserName}\My Documents}
After this, you should be able to start the launcher/game again.
