I do get a problem with NWjs and Construct 3.
This is because I can't get folder creation to work in the executable. I thought it might be something I wrongly programmed myself, but NWjs code works perfectly in remote preview.
I leave you a small example program, so that you can analyze it and tell me, please, where I have made a mistake or if it is something specific that will be fixed in a future version of C3.
Note: The only difference I see between C3 and the NWjs, is the version.
NWjs (sdk, as you recommend in the tutorial) is the nwjs-sdk-v0.50.1-win-x64 AND C3 when exported has the 0.50.0, Chromium 87