You have a Sobi catalog and registration can not be run.
You can not log into your catalog Sobi Multiselect fields can neither open nor you can get your category from your category tree (tree does not open) select.
This often happens when the application is cached in Sobi.
If you have your scripts and CSS Compress any "Join and minify" for your scripts and also cached then this problem occurs. Often, also if you use JOTCACHE.
Here you have to do the following:
The login page of your SOBI exclude so that the page is not cached, do not compress the application, and not merge with another script, then it will work.
Good luck in your registration!