A user found the culprit: The First argument must be one of type string,... error happens if the XModule root directory is changed from the default one:
"I have done some investigating about this issue, and it seems that the local OCR works fine if you install RPA extension and Xmodules to the default folder and also keep the default Home folder in the FileAccess XModule settings:
… \Desktop\uivision
If you change that, then it seems that the local OCR will not work any longer (at least in our case). If I change it back to that, then it works fine. Are you aware of this and will this be fixed in the upcoming versions?"
=> We confirmed this, and will fix it with the next update. Meanwhile, as workaround, please keep the default XModule home folder.