Qlik Data Gateway Direct Access will release soon a new version (within the following two months) with capability to read from files, perhaps that could be the option to explore.
For the issue in QDT that you have, is that all what you can see as an error? Any specific log that you are looking at ? Any errors in the windows logs?
KInd Regards.
Don't forget to mark as "Solution Accepted" the comment that resolves the question/issue. #ngm