I read the postprocess mesh with mesh read. Is it correct?

Instead of using "meshread", you shoud probably input inside the postprocessor two files:

Check the manual for the sintaxis format.

If the mesh is already in the preprocess, it is necessary only the results file. It must have the name MODEL.flavia.res and be inside the directory MODEL.gid In this case, when going to postprocess this file is automatically read.