I've just copied my installation to a USB stick so I can run it on my work computer. When I launch ffxivboot.exe I get this error

'An error has occurred in the script on this page
Line: 20
Char: 2
Error: 'Global' is undefined
Code: 0
URL: http://frontier.ffxiv.com/version_3_1_win/index.html?
rc_lang=en&time=2017-06-07-13

Do you want to continue running scripts on this page?

Yes No

Whether I click yes or no, I get a blank version of the launcher window and can't proceed any further. It may be worth noting that when I close the window, I get a prompt asking "Exit FINAL FANTASY XIV?", which tells me the launcher is running, but the script error is stopping it from displaying the web content. Any help would be appreciated.