Can't create new projects since upgrading

I think it might have been something to do with Softaculous. I originally used this to install XOT.

I have just updated the Softaculous record for the installation, refreshed the Xerte main page and been able to create a new project.

Does this make any sense? Anyway, thank you for your time!

No, not really, but I am glad it's working for you.

Just as a data point, the same thing happened to me. It didn't clear up until I tried toggling my ad blocker (uBlock Origin on Firefox 63) off and back on.