It seems to specifically only be an issue when adding to a deck that had a card in it that currently doesn’t exist in the card database.
I can get around the deck errors by copying the deck to a new slot and adding a card, or by using the trashcan icon in the upper left of the screen and starting over. Otherwise there is no way to replace the empty card without an infinite error loop.
Surprisingly, I can play with the deck. I haven’t played enough games to see if Demolish is drawn, but the game recognizes a valid deck when starting a match.
I definitely want my demolish back!
Oops I made a thread about this. Couldn’t remember the name. Yes, demolish vanished.
Thanks a lot! It works. Rebuild the deck is a good solution!
@Brigby I tried reinstalling several times and that did not fix the missing card issue.
Hi Everyone. I’ve relayed this info to the development team, so they are aware of and investigating this issue. Once I have an update to provide, I’ll be sure to communicate it in this thread. Thanks for everyone’s patience!
Just figured I would check in and say I found I am having the same issue(demolish is missing from my red decks) tonight when I logged in for the training grounds reset. Let me know if there is anything I can do on my end to help.
I figure demolish is still in the old deck lists, but doesn’t point to anything else anymore so nothing displays, but you can’t remove it normally, so adding a replacement card makes it think there are 11 cards in the deck.
The Trash button wipes the whole deck and starts again so gets around this problem.
My problem with Black Vise was my fault, nothing related with this bug
I still cannot see some cards, they are not even in the whole list of cards.
Try yourshelf filtering the whole list of origin cards and try to find Demolish.
I’d do if I could log in to the game… 
It was for @Brigby to see an example of this bug, not for you 
Hey, Demolish and cancel are back.
Thank you @Brigby
Glad to hear that those two cards are back in the game! Is anyone else able to confirm if Dual Shot and Sure Strike are available now as well?
@Brigby Dual shot and Sure stroke are also available in the library.
Fantastic. Thank you for the confirmation!