Hi there,
Sorry for the delay in responding.
I am not sure if you have solved this, but I have seen this issue a number of times before. Please clear your browser cache, then do a hard refresh of the CJT dashboard page. Clearing the browser cache is required especially when you are migrating to a totally different version of CJT as it needs to pull in the latest scripts and stylesheets.
I hope this helps.
Regards,
Damian Baker