what are all these dozens of "_sensor" devices?

I’ve had the same devices set up in the garage for over 2 years now. I very seldom use my vera to remote control anything, as I use its automation to do everything and it runs pretty well.
However, I logged in the other day and there are dozens of “_sensor” devices (see attachment). Any way to tell what they are connected to? I have several on/off zwave devices (switches, etc), two sensors, and then a ‘power meter’ that connects to the breaker box. I’ve never used it, so if that’s what’s creating all these things, I will gladly remove it. Any way to remove these things in bulk?

Also noticed I’m running 1.6.641, and they are recommending 1.7.730. Any problems with updates? I generally don’t update anything unless there’s a problem, but I like having the two ‘GUIs’ - the ‘advanced mode’ and ‘simple mode’.

You ran into the “ghost devices bug”. Should be solved in previous firmware, but was not entirely, so next firmware according to MCV.

Is the firmware update straightforward? Not going to lose anything or have to recreate , etc? Is it just done through the vera interface? (i.e. ‘firmware’, click ‘update’, etc)?

For me it was last time. Although it introduced some new problems.