wrong module is required by model?

Hello,

I have a simple heat transfer model that used to work.

Now, when attempting to load it, COMSOL returns the following error: could not obtain license for CFD module//license error -4// Licensed number of users already reached.

I am using university 'floating licence'
COMSOL version 4.1.0.88

Is there a way to disable the use of the module in the model or investigate what the problem is?

Thanks
Vasily