Meshing Error

New to Simscale. Imported a new geometry from CAD with no problems. Went to mesh and I get an error saying: “The tesselated surface is not closed… There could be a problem with the CAD geometry.” in the geometry I have three shape volumes and perhaps the error is caused by surfaces of these volumes intersecting.

Please help, not sure what the error is caused by.

Not sure how to attach the project…

welcome @jyates

It is not possible to mesh intersecting elements, what can be done is fuse merge one solid or work in a perfect assembly.
Try making a solid CAD assambly or only one cad of one solid.

https://www.simscale.com/projects/jyates/eductor_induced_draft_in_fired_heater/