Thank you, I have reviewed and restructured the files and folders on the hard disk. I have not found files with non standard characters.
And after a reboot, my AXT-1800 started to show all the folder and files. So currently, for this unit the problem seems solved.
Regarding my older units (MT1300) I am still seeking for the right firmware version to maybe get it running too.
I have installed the beta version 4.3.2 - and I would like to go back to 4.2.1 or an older 3.x version. Unfortunately there is no 4.2.1 version available on the download site, and the version 3.2.16 is refused for manual upgrade with error message “Testing the firmware with sysupgrade failed.” .
It seems I am somehow stuck and need some direct glinet support for this unit.