@martin great! Thanks a million!  I am impressed by your support.

@sofy I sent a new mail with the details.  Thanks.

@alvina you should have received an mail with the login details.

@robert No, nothing in functions.php To test that it is not hard-coded: when I change the url for the registration and login page in the wpforo se...

@robert That will indeed be it. But... do you know how the AJAX script gets added to the html source?  I didn't change anything when updating...

@robert the URL is bstore . be / fora Check the error on the var wpforo statement - seems like there is a syntax error. the theme is modified, b...

Robert, thanks for your quick reaction. I deleted all caches and disabled optimizer/caching plugins. The problem is still there. Ajax functiona...