Cannot create Folder or File on Flash drive - operation unsuccessful

[Krammig]

A Flash drive when inserted into the phone shows up fine as a OTG USB
It is possible to open it, Browse the folder and open the files on it.

However, when trying to Create a Folder or File it has a message "Creating File" but then says "Operation Unsuccessful"

Format of the Flash drive is FAT32. Have tried several different flash drives with the same issue on all. Tried exFAT just for the heck of it but the partition is not accessible.

Tried on Android 5.1.1 and 7.1

Odd thing is though - the built in Android Explorer can access the flash drive fine, it can Create both files and folders, delete, open files etc etc.

So if the built in Android Explorer can, what is it about this app that cannot ?? Permissions in the app or similar ?

[Krammig]

Anybody awake in there ????

[NanyangTaiji]

It is a problem of not getting the permission of writing external storage.

[Krammig]

That is not necessarily so.

The app has been compiled with the necessary settings to allow for writing to external storage. However that error persists.

Have you actually tried it yourself ? because it does not work.