Yes i am looking in to the same issues.......
Not that i have them, but i created them on purpose.
How does this happend, when you restart your phone with a regulair shutdown or a forced shutdown.
A forced shutdown often results in that in the next boot wp needs to scan the card for errors.
The reason is that it could not close the sd cart propper ( same as you remove a usb during a running proces on your pc ).
Reinitialising the card can only be possible when wp has scanned it for possible errors.
Scanning can take some time, a specialy with large cards.
You notice that surtain apps are "grayed out" on your homescreen during that proces.
Note. of course only the apps witch are installed on the sd card.
Tip............shutdown the Phone, put the card in your pc/laptop and then scan for errors,
its a hell faster than when you do it with your phone.
Your phone won't scan again during the next boot.