Robinvde Robinvde It looks like you might have deleted the geometry that was connected to the zGeo nodes that are complaining before you saved.
If you select those zGeo nodes, one at a time and break their connections (they pass through other nodes first) to the zSolverShape node, that should get you back into a working state.
When deleting geometry, it's important to use the menu option, as Maya will just delete the geometry alone and leave all of this other stuff in your scene.
If the error persists, you can send the file through to "support at zivadynamics dot com" and I'd be happy to take a peek.
-jj