I have a Mac Pro 2012. I just updated to High Sierra. Seems to have been a mistake.
Everything seemed to be working fine for an hour or so then I started having some problems.
1) It would not let me authenticate/log in to imessages. This didn't work from the get go. To fix this I rebooted a couple times, reset the NVRAM https://support.apple.com/en-us/HT204063
Imessages was working.
2) Now I started seeing flickering on the screen after I fixed #1 above. Everything was flickering while using Chrome - very annoying. I would not be able to use the computer like this. In Safari, it wasn't flickering but the graphics were very screwy. I tried to run the diagnostic (Hold D when booting). Everything is OK.
3) Now I cannot boot up to my regular 256gb SSD boot drive. It keeps booting to Disk Utility and prompting me to restore from backup. At first, my regular boot drive didn't show up so I selected a drive that I don't use which it will erase. It failed a few minutes in. I tried again. Same - failed. Third time, now my regular 256gb SSD drive shows up so I try to restore to that drive. Failed. Tried a second time to this drive. Failed. So is my 256gb SSD corrupted b/c of this new file system?
4) I'm trying to reinstall OS X Lion 10.7 since that's another option they are giving me within the disk utility. Hopefully that will work and then I can restore my Sierra installation.
Some other data points
a) updated a brand new MBPro to High Sierra. No issues.
b) updated my iPad to iOS11 and had to immediately roll it back. The airplane mode doesn't work right - it's supposed to leave wifi and BT in whatever state they were in before you do airplane mode. Instead it turns them both on each time you deativate airplane mode. Very annoying to have to turn off BT which I rarely use and wifi if I'm not using it.
Anyone else having similar problems?
**sorry if I put this in the wrong space.