We need to see the rest of the parfor loop - unfortunately, errors from parfor are reported as occurring on the first line of the loop, even if that isn't where the error is really coming from. It would help if you could try to narrow down your problem to a minimal reproduction that demonstrates the problem.
Transparency violation errors occur when you do things that try to access the workspace of the body of the parfor loop in ways that the parfor code analyser cannot understand. This includes: eval, assignin, load, save, running scripts etc.
