Output results required error and changing material error

Dear Colleagues,

During my preliminary calculations of vertical vessel in Vessel (no nozzles, basic settings, only trays and packing defined for rough approximation of mass distribution, some wind parameters), I have encountered an error.

Some of calculation runs passed easily, however after some small changes like material and some dimensions, calculation is aborted with error "Output results required". I've read that somebody had this problem before, but as no solution was posted, I ask this question again - did anybody encounter this error and how he get rid of it, where to look, what to change? Error occurs just after internal pressure calculations try to start. If needed, I can provide model file.

And my second question. I cannot change material "en masse" by right clicking on 2D representation and using "Change material" window. Wherever I try to filter by product or material class, Vessel simply closes without any further notice. This is independent of the model I am trying to modify. Is there some hot fix for this problem or any other solution?

Thank you in advance,

Regards,

Krzysztof Skrzypek-Markiewicz