Can't interact with USB stick in any way (but can see its contents)

[Cwpute]

I can't copy files from internal to usb key plugged into the phone. There is plenty of space on the usb key, and i tried with my phone's built in file manager and it worked withouth a fuss.

Simple File Manager gave me two notifications vhen i tried to copy or move the files:

The second notification showed:

The issue might be related to this: https://github.com/SimpleMobileTools/Simple-File-Manager/issues/210

[tibbi]

to what folder are you copying? Try copying from a different source to a different destination folder, just to see if it behaves the same

[Cwpute]

I'm copying from to root of the usb stick. I cant test other folders right now as i dont have the usb stick at hand

[Cwpute]

Ok i just did a bunch of tests and the issue seems to be even wider as any action on the USB stick ends with some java exception like the ones i screenshoted before. I reckon Simple File Manager asked for permission to access a bunch of other separate folders some time ago, folders within the phone itself. Maybe it somehow doesn't have permission to acces the USB stick but can still manage to show what's inside ?

[tibbi]

not sure, try reinstalling the app just to reset everything

[Cwpute]

I reinstalled the app with the USB stick still plugged in. The app prompted me give access to "all files", which i gave, then prompted to give access to the USB stick, which i did too (it sent me to the built-in file explorer on the root of the USB stick and i confirmed i gave SFM access to it). Still, no cigar. I can't make any actions on the USB stick, and the app still throws me those java exceptions.

Is should have specified this before but this is my phone:

• Nokia TA-1157
• Android 11
• Simple File Manager 6.14.4 Pro

[tibbi]

Ok, some USB related improvements are on the roadmap, sadly it is really difficult to work with.

[StevanWhite]

In my case, the app sees that a USB storage device is there, but displays nothing, although other file manager apps see the contents with no problems. This is Android 10.

I've been thinking about how these things should work, and testing various apps. Here are some points:

App should

1. allow navigation and basic file operations on USB partition.
2. support multiple partitions
3. handle read-only filesystems and devices appropriately (visibly indicate is read-only, warn user that filesystem is read-only, if they try to write to it.)
4. display filesystem labels properly
5. respond gracefully to on-the-fly insertion and removal of device.

Also, if user has selected app to open inserted USB by default, then USB insertion should open the file browser activity for the drive, as directly as possible.

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Some examples of freely-usable (but not all open source) file managers that handle USB pretty well:

• Files (google.com)
• Cx File Explorer (cxinventor.com)
• Owlfiles (skype.com)