[pmwiki-users] PHP error "Only variables can be passed by reference" in upload.php

[Benjamin Henne]

Hi,

I just upgraded pmwiki from 2.2.4 to 2.2.15. and now get the following 
error:

  Fatal error: Only variables can be passed by reference in
   /is/htdocs /wpxxxxxx/www/scripts/upload.php  on line 225

I copied all new files over the old ones.

If I disable uploads, everything is fine, if I enable it, I get above 
error message. I cannot disable it, because this means all attached 
images would be gone. Is this a known bug and is there a fix?

Regards,
Benjamin