Hi,
Thank you!
Okay, the problem is, that the plugin is actually returning a response, but something is changing the output of the HTML code, that the plugin ajax handler returns. The starting response delimiter is changed from !!ASPSTART_HTML!! to !! ASPSTART_HTML! on the english version (adding a space, and removing a ! sign from the end). On the french version page it looks fine.
I have not seen anything like this before, but I am guessing that the translation plugin is somehow tempering with the ajax responses, and makes some sort of relacements. If there is a translation configuration, or some sort of a manual translation section, make sure to check if there isn’t any rule that changes !!ASPSTART_HTML!! to !! ASPSTART_HTML!, because that is causing the problem.