With an iRulu X1s Android 5.1.1 ("Lollipop") tablet, connecting in MTP mode via USB to libmtp 1.1.9-3ubuntu1 on stock Ubuntu 15.10, I get this in syslog:
Feb 20 14:15:27 toucha org.gtk.vfs.Daemon[2302]: PTP: reading event an error 0x02ff occurredDevice 0 (VID=1f3a and PID=1007) is UNKNOWN. Feb 20 14:15:27 toucha org.gtk.vfs.Daemon[2302]: Please report this VID/PID and the device model to the libmtp development team
Anonymous
I have added the ID to git for the 1.1.12 release, thanks!