Simulation Run - A multi-region mesh was assigned - this analysis-type requires a single-region mesh

Hello:
I have this Simulation Run for a blower that failed with the error
"A multi-region mesh was assigned - this analysis-type requires a single-region mesh. "

I have a volume for the Flow Volume and one for the Rotating Zone.
Meshing went through no problem.

My project link is:

Help would be appreciated.

Thank you in advance