[Babel] Issue when saving a linked translation

I have issue with Babel on a website.
I’m using Babel 3.0.0 and when I try to “Link to existing resource”, the popup is appearing but when I set the correspondig resource, the modification are saved “indefinitly” and the modification is lost if I refresh the page.

I have nothing about this problem on the MODX log

Another strange thing : if I go on Extensios > Babel, the page is nearly empty :