Cashing spoils sets

I have 5 spoils and I am being told that I need to cash in 3. However, I don't have three of one color, so I can't cash in a set, but I seem to be unable to do anything else or pass, so am unable to take my turn. Thoughts?
Conquer Club, a free online multiplayer variation of a popular world domination board game.
http://www.tools.conquerclub.com/forum/
http://www.tools.conquerclub.com/forum/viewtopic.php?f=6&t=127137