iMac says update installed, but won't restart.
Mid 2011 iMac running MacOS High Sierra.
I recently had an issue installing a software update on my iMac. When installing the update, everything seemed to go fine, until it was time to restart the computer. Once the download of the update had completed, I clicked to restart the computer... it wen't to the usual grey apple screen, but then the progress bar stopped and hung up on the words "restarting". It never restarts... it just hangs there endlessly... I left it for 8 hours once to see if, due to age, it was just being slow. No progress. I can do a hard reset, and the computer starts up fine as normal and functions properly. The weird thing is, according to the info on my device, it says it installed. 10.13.6. and yet, every-time I use my computer, the app store is prompting me to restart to install the update that, apparently, it has installed. Is my 2011 iMac toast?
iMac Line (2012 and Later)