"Ignore Rule" produces error: "Bad token. You seem to have followed an invalid link."

Whenever I click "Ignore Rule" on proofreadbot.com it gives me a red error message: "Bad token. You seem to have followed an invalid link."

To confirm this, my "Ignored Rules" page http://proofreadbot.com/user/21460/ignored-rules shows no ignored rules.

Type: 
Bug
Status: 
Closed (fixed)