Buttons disabled after login

Hello,

I want to use the EverSync 1.2.0.0 for IE application. I can log in sucessfully, but if I switch to the "Bookmarks sync (advanced)" register all buttons are disabled. Sometimes a popup appears that an error occured and the developer can be informed. Platform is Windows 7 64Bit with IE11.

How can I solve this?

Thx, Markus