Neither Bluetooth connection nor USB connection is able to transfer files from Android smartphone to Ubuntu 18.04. Same devices with Ubuntu 16.04 did not show any problems. When starting Nautilus, it shows the android device, but when opening it, it stays busy and does not show any results.
Ubuntu 18.04 kernel: 4.15.0-20-generic
Android Smartphone Samsung A3, Android 7.0
kernel.log messages when connecting the phone via USB seems to be OK:
May 12 05:39:53 len kernel: [69577.277832] usb 2-1: new high-speed USB device number 28 using xhci_hcd
May 12 05:39:53 len kernel: [69577.427116] usb 2-1: New USB device found, idVendor=04e8, idProduct=6860
May 12 05:39:53 len kernel: [69577.427122] usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
May 12 05:39:53 len kernel: [69577.427127] usb 2-1: Product: SAMSUNG_Android
May 12 05:39:53 len kernel: [69577.427130] usb 2-1: Manufacturer: SAMSUNG
May 12 05:39:53 len kernel: [69577.427134] usb 2-1: SerialNumber: 5203f8dd51fc142b
When starting Nautilus from shell and opening Android folder, I get the following message:
Nautilus-Share-Message: 05:41:13.818: Called "net usershare info" but it failed:
Childprocess »net« could not be executed (No such file or directory)
My workarround at the moment: installing SSHHelper on Android and using scp to copy files via SSH.