coll appear as a "No such object". Why?

Suddenly the coll object act as a "No such object" when choose it in max. Although the object file is in the folder its supposed to be. When i ask for help file the help file opens, but the coll is sort of red and not acticated(see picture attached). Also if i find the object in the the folder manually and double click on it, it works in max too.

But this is really super annoying. Anybody else had this problem?

any help would be very appreciated.