Quartus II ver 6.1 Licence Problem

We have been using Altera Quartus II ver 6.1 design software until we have a licence problem as:

"Licence file does not support EP1S10F484C5"

By the way we have been using these kits more than 5 years. The processor on the kits is "Cyclone II, EP2C35F672C6E".

Could you please help us about the licence problem.