I wanted to contribute to this Communities site for others that may come across this problem. Also - wanted to give thanks to Pareej Pradhan for helping us to solve this problem. We are new to TDM, but we encountered this error when attempted to Mask/Subset in flight from the source while executing the export batch file.
More context: We were attempting to use Transformational Maps to mask and subset in flight from a source. We used the Windows DataPump Masked Export utility from GTSubset. Here is a screen shot of the error when we were attempting run the export batch script.
What these errors mean is that there is a GTPUMP directory at the source that didn't allow this user to write to it. In order to solve the problem, we had to get our DBAs involved to open up the permissions on the GTPUMP directory at the source.
for the exportdp.bat file is
Username password GTPUMP
Hope this helps.