OK, I found the problem:
the IE javascript error only occurs when you set the "Display Type" from "tab" to "div" (admin: components - community builder - tab management - _pg_ProfileGallery )
before I found that, I tried the following:
-uninstall CB
-reinstall CB (and therefore reinstall the gallery plugin)
this was not the reason, but it caused another problem, I had double entries for the gallery in the tab management
I would like to use the display type "div", do you have any idea how to fix the javascript problem?