I'm running the game on an ipad pro with the new OS.

 

I had the game freeze while loading a quest adventure with 6 characters.

 

I reset the game, and now it will not let me add one of the characters to the party. It changed her name from Kyra to Kyra 4 and there's a 'locked' symbol by her portrait.

 

I tried 'continue' from the main screen, but only my story mode characters are listed there.

 

I also tried just using one of my other characters to start and quest and then quit, but that didn't change anything (it let me start a quest with a different character, but afterwards when trying to start a new quest it still won't let me choose Kyra 4)

This has happened to me twice.  The first time I didn't care since the character was just level 2 and the only thing that bothered me was I couldn't delete it.  Now it's happened to my more experienced character and I can't continue in Quest mode.  How do I unlock the character?

I figured out a "workaround". Since my quest parties got broken up by this issue, I was able to transfer the better cards from the unaffected characters to new versions of their characters by putting them on someone else. This way I can reform the party from level 1 with some of the better stuff from the old party. This is not perfect but does make restarting everything less painful.