We have an issue where the forum/uploads/javascript_global/root_library.js is missing

Can we simply upload this manually? If so where can I get a copy.

Thanks!

You would upload a fresh set of files from your client area

On this one, please clear the cache from your admin CP, which should resolve. If not, you can try disabling an application then re-enabling it

Thanks @Marc clearing the cache fixed it 👍