With my Iris+, today, when I try to calibrate the compass on Mission Planner, it will only go up to 6 samples, and lock up, also only starts to show the first globe moving, before it locks up. It has worked before many times, shows 2 globes, (both compasses) and I could rotate, and pick up as many samples as I wanted. Tried this on my laptop and desktop, both with the 3DR radio connection, and connected directly to the computer. Same thing, goes up to 6 samples, and locks. Uninstalled Mission Planner, and re-installed the latest version, same thing. Am I loosing my mind, or what? 
Weird for sure. This Iris+ flew fine earlier today, now the compass will not calibrate, no matter what I try. Hooked up my “other” Iris+, and everything works as supposed to, calibrated compass, both, no problem. Soooo, the problem must lie within my Iris+ that won’t calibrate. Any suggestions? I’ve been trying all day! 
try a param reset on the bad iris.
ie full param list, reset to defaults.
you will need to setup everything after that though
I pulled the top off the “not calibrating” Iris+, and found NO loose connections, etc. etc. Still won’t get past 6 samples on the calibration, then locks up ??? VERY weird. I figured last night, I’d try re-loading everything from scratch. Also will not hold calibration using APM Planner either. Will post results after I reload the parameters, etc. 
Reset parameters to “default”, now it locks up at only 3 samples… And still only shows 1 compass active for just a second, before it locks. I’m at a loss. 
OK, this morning, I tried again, and she’s back to normal. Don’t ask me what I did ??? BUT, in Mission Planner, there are two places where you can select parameters to load. One “drop down menu” comes up on the far right side of the screen. I always selected Iris+ w/GoPro front mount, as that is the configuration I have. However, there is another place in Mission Planner, where the drop down menu for parameters, is in the middle lower part of the screen. Seems to have the same selections. This morning, I used that location, and loaded up Iris+ stock parameters, (no gopro etc. etc.) and everything came together. Did all the calibrations, and flew. Now need to do an autotune, as the stock PID’s are slooooow. I still have no idea what caused all this to happen in the first place. 