what is this in ADS while running momentum?

WARNING:could not create the dataset since no files could be found..... saving project files.
---------------------------momentum stopped----------------------------

how to rectify this in ADS while running momentum..

We can not answer your question with out enough information. But is looks like you
have a dataset object in your schematic and it can not use it in Momentum, but
that is just a guess

It may be a program crash due to some convergence problems or simulation engine had a bug under this particular case..

What is your version
You can't running ads 2009 on 64 bit
You should install it 32 bit to running simulation without any problem
Or use ads 2011