'Your configuration is invalid' Sansa Zip Clip + ADDITIONAL DETAILS INSIDE!

[apachey]

I had some veery weird troubles with my player, so i reinstalled stock firmware.

but now Rockbox Utility says 'Your configuration is invalid' through MTP. When i tried through MSC, i found 2 removable devices in (my player currently has no SD card) 'my computer', first one is empty and the second isn't working (opening it shows 'insert device in I:\').
Though, Sansa Updater and computer can detect player pretty well through MTP

what i should do? Looks like there is some dead rockbox files that i can't reach out