Thanks for the answer, but I am afraid that it did not help. Even if the first parameter (suggestedFileName) is provided, the file dialog is not opened.
Curiously enough, the same code works fine if manifest version 4 is used (and the “requiredPermission” section is removed from the manifest.
My guess is, that probably some permission is missing in manfest V.5., but which one???
kindly mark the reply as a solution for ease of browsing for other members.
also I almost missed the issue due to bad code formatting, in the future formatting your code will make it more likely for people to be able to help.