Any ideas?
Sure. Remove the plugin and run for the hills. Don’t look back.
This plugin absolutely should never be run on a multisite installation. Allowing people on a multisite system to run arbitrary PHP code is frankly insane.
That said, I’m glad that at least that particular check works, because admins of individual sites on a multisite installation do not have the “unfiltered_html” capability and so should not be allowed to use arbitrary HTML code, much less PHP code. On a multisite install, only Super Admins have that privilege, and only they should be able to put PHP code into the widget.
Still, don’t use this plugin on multisite. Heck, don’t use it anywhere. There’s no good reason for it.
Intersting stuff from the horse’s mouth, as it were 🙂
Thanks.
Kind regards, Mitja