I'm in the situation that i cannot surrender my EQuivocate license. In the ilok manager app, I cannot tick the checkbox and the license is greyed out in the surrender dialog box.

Is that an ilok manager bug or is there something wrong with my licenses?

It probably means that your license is not available.  It's either on an iLok that isn't plugged in to your machine, or it's on a computer which is not on and attached to the internet.  Is this the case?

If so, the most guaranteed fix is to manually deactivate the license from the installed iLok/machine by right selecting the location in the left pane of iLok License Manager, right clicking the license, and selecting Deactivate.

Dan