I'm having issues with my phone unmounting my SD card (formatted as internal, stores multiple apps) upone restart. This has happened twice in the last week. On reboot I get a notification saying the SD card has been unmounted and all apps that were on the SD card are greyed out on the home screen. I tried restarting the phone and removing and reinserting the card, hoping that it would mount and restore my apps, but had no luck.
Each time this happens I have given up trying to fix it and resorted to formatting the SD card. The first time this worked fine. I was able to format the card from the phone and reinstall my apps. The second time has been more difficult. I format the card as portable (which takes <1 min) then format again as internal (which takes much longer) but still see the "SD card unexpectedly removed" notification.
I got into Settings > Storage & USB and can see the SD card. Is shows some space is used (~44MB) but I cannot change the default internal storage location to the card, so I restart the phone, but nothing changes.
I have continued to try format the card as internal and started watching it a bit closer. I noticed that the the formatting process gets to 20%, stops, then the app closes and I get the "SD card unexpectedly removed" notification.