UPDATE 25/09/2020 : 'An asset error occured during your last play session. Validating asset files to ensure stability, this may take a while.' Followed by a very long verification of assets.

Issue still happening every day when I first launch the game, even after updating video card drivers, I still have the same problem.
Started happening 2 updates ago, I thought your last update would fix it but no. I took my first screenshot of the error September 19 2020.
I managed to reproduce the error.
Please note, if I launch the game, wait for the assets to verify then close and reopen the game I do not have an assset error, I tested this several times.

If I play 'play standard' game then exit and reload MTGA, I do not have the asset error.
If I play 'Standard Ranked' then exit and reload MTGA, I do not have the asset error.
If I play 'Quick draft Ikoria' then exit and reload MTGA, I do not have the asset error.
I played till I won an Ikoria card reward, then exit and reload MTGA, I do not have the asset error.
I played till I won a zendikar card reward, then exit and reload MTGA, I do not have the asset error.
When I completed an Ikoria quick draft and opened my Ikoria pack reward, then exit and reload MTGA, ERROR ERROR ERROR....

Now I get the error screen again ' An asset error occured during your last play session. Validating asset files to ensure stability, this may take a while.'

To be clear, I was not using any addon's or trackers or any other application, the only thing open on my computer since I rebooted was MTG arena.

Presently using Magic the gathering Arena Version 1.1200.4.3152(3152.817437)
On windows 7 Home and windows 10 Pro. Same issue on both machines.

If you need more information please contact me.

Other errors I noticed in the game... the display of Ranked info after a non-ranked game appears to be resolved and not happening anymore.

There are still issues with the emotes in game, if an opponent selects nice, my side has a thanks response, when clicked thanks it says nice on my screen instead. So that still needs some work.

Whenever I try to login using my account, the launcher will go through preparing assets then it will give me an orange spinning ring that says waiting for server.

My Husband also has MTGA so I had him see if his game works, it does. his works fine on his computer. Except if i try to login on his computer it prepares assets then gets stuck at waiting for server again.

I spent 3 days going back and forth with tech support, changing settings, uninstalling, reinstalling, using different internet connections. They checked to make sure I don't have any bans or whatever, and then they sent me here.

It started on April 16th, the day of an update.

For the daily deck unlock quest for the white green set I received the rotated unusuable Selesnya Conclave deck instead of the standard Selesnya: To Adventure! deck that I was supposed to receive.

The first three decks (White Blue Starry-Eyed, Green Red Stomp Stomp, and Black Red Line of Fire) unlocked fine. Then Green White Selesnya Conclave is rotated and unusable. Then the following day the unlock for Black Blue Mutation Station is also fine.

I signed up and started playing on September 18, 2020. I finished my colour challenge and unlocked the correct White Blue deck on September 19, then unlocked the correct Green Red on September 20, then unlocked the correct Black Red on September 21, and then unlocked the incorrect White Green deck on September 22, and finally, unlocked the correct Black Blue deck today September 23.
(WB and RG decks might be reversed I'm not sure which I got first, don't think it matters.)

I would really like to have the proper White Green deck. This has to be a mistake/bug/glitch. :(