I think I've sorted the categories issue.
You may need to clear your cache again, but after that, the mobile version fo the site should be back to how it was before.
I've updated some files.
For mobile users, the cog edit wheel function should now work.
The Hamburger menu now works, but the categories aren't showing. I'll work on that later.
Can some mobile users confirm it works for them?
I've updated the forum to the latest Vanilla software, and the latest php engine.
It should all run as before, but if you find something no longer works, or isn't working in the same way as before, please let me know on here.