problem in cosmos works

Dear All,

One of mine friend is working on Cosmos Works. He got a very strange
error as mentioned below.

"I have a problem while accessing Solidworks transient analysis. Error
"an unknown error occurred while accessing an unnamed file"

Geometry: simple cube

boundary conditions: temperature constraint on all the outside
surfaces of the cube.
initial temperature also given.

transient simulation is being run on Cosmos Works.

After a complete run of transient simulation of about 2-3 hours, an
error saying"An unknown error occurred while accessing an unnamed
file" popped on the screen."

Can someone let me know what can be the cause and whats the remedy for
the same.

Thanks & Regards

Deepak