Ha, now I have this message after upgrading to 2.1.1. I'm not using the staticpage plugin....

Hello everybody. All of a sudden I'm getting a 503 error when I try to move a plugin between sidebars or delete it. I can install new ones OK and everything seems to be working fine apart from this. It certainly used to work alright, and I haven't tinkered with anything. I've got V 2.1.1 (upgraded f...