You have not set the path for your PCell Evaluator.
When you are instantiating the PCell( Creating submaster), The Pcell code should be evaluated.
Can you please let me know which library/PDK you are using.?
Most likely there is a not-set parameter, or a badly set
one that is not type-checked or called-back, or there
is an error in the PCell funcrions embedded in the cell.
Sometimes there is more detailed info spewed into the CIW
that might be a clue.