I am getting this a lot, mainly when altering BRICK info (alias, names etc).

Invalid token.
1. Maybe an other interface has been loaded (Remember that you cannot work on two simultanous pages.)
2. An ajax conflict. Wait 30 s and retry.

Waiting does make the error go away, but its happening a lot and is a little frustrating.. though VERy minor/ I am not working stupidly fast, or forgetting to close down other windows, there is no real reason for it to occur.

Also just happened when altering a field in a grid view.. so when a little 'sub window' pops up.. over sensitve error?

Yes, this is normal.

Hard to fix for the moment please work with that. It has been announced.

Moved in Pending

Fixed since long time.
Closed ticket.