I have had many instances of the error ‘Cannot Find Solid Bodies associated with the material’.  This error has occurred with small or large models.

The error occurs when trying to edit Solid Materials definition or when starting to solve a new or revised model.  In this case it is attempting to add Tube3<3> to Solid material Steel Stainless 321.

Other components have had solid materials edited without errors.

Fluid opening definitions appear correct.

Model volumes have been checked.

Things tried:

Assembly rebuilt.  This has corrected error sometimes. (?)

Existing Solid Material definition deleted and started a new Solid Material definition.  This appears to correct this error sometimes. (?)

Saved and reopened assembly.

Project rebuilt.

Tube3<3> opened , rebuilt saved and assembly reopened.

In this specific case, the error was corrected by suppressing the HE Box 3 component, selecting the Tube3<3> component and defining Solid material.  Then the HE Box 3 was unsuppressed and Solid Material defined for it.

This error appears to be random and the correction often seems to be the random trial of many things until the error goes away.

Can you provide any explanation?  The model files can be sent if needed.