this error had stopped any simulation process (A setup with 57 regions is being used in a single-region analysis type. Please make sure that all regions except for one have an Advanced Concept assigned to them).
Hi, and thanks for using the forum!
For an incompressible simulation (or convective HT), the only part in the model must be the flow region.
If your solids are still there, please remove them using the CAD edit mode with the Body - delete operation.