I am working on modelling and simulation of a 3D Simple silicon Nanostructure device. However when i try to run simulation, the comsol error appears;

Internal error in solutionMerge

Variables property does not include all variables in xmesh.

Does anybody knows about this error? However i tried to fix the Mesh element size from small to large size but it still appears. Any help regarding this concern would be much appreciated.

Thank you.