Having finally got around to updating to Mint 18, I am struggling to get it to connect to my phone.
With Bluetooth, I previously had various glitches at various times, but it simply worked for most of the time. This one is seeing it and pairing successfully, but not connecting.

I have successfully sent a file to the phone, but cannot yet send one back...

Connecting the phone into the USB, the phone keeps rebooting itself.
It has never done this before on this laptop, but it did do something similar on a very old laptop: I put that down to an incompatibility with USB 1, but I guess I got that wrong.
I will check in a moment if this laptop still talks to the phone under Windows, to confirm there isn't a hardware problem.

Previously the phone showed up as an option in the network manager, but now it doesn't; lsusb lists it as "MediaTek Inc. S103"
Further experiments have found that it only reboots when set as a COM port: it doesn't reboot when set to other options, but neither does it connect properly.
The COM port option is what I have previously found to work to connect Linux to t'internet.