As said earlier in this thread:
Same issue on PC (from the Jan 26th patch/update?)!

Ok guys, you need to be very tough, but I got it working - HOLY ****.
If you are on Windows 11 and stuck at the initial screen with "error updating data - please check your connection and try again" then stick to my words now (translation might not be 100% correct, I am running the German Windows 11 version):

1. Go to Settings
2. Time and Language
3. Language and Region
4. Administrative Settings (This option is a bit further down)
5. Language for Unicode-incompatible programs / apps
6. Check mark after opening the region settings "Beta: Use Unicode UTF-8 for worldwide language support."
7. Restart your system and smile forever :)

Same problem with Epic, Steam and MTG Launcher. Nothing works :(

Wondering if WotC even reads these comments. Always when trying to install the game the installing process ends in asset manifest step, error updating data. The problem seems to be between installing software and mtga servers.

In UTC_Log it says this:

[2] FD Lookup failed: Partial byte sequence encountered in the input.
Parameter name: string
[2] Using fallback FD
[81] [TaskLogger][Accounts - Startup] Player has rememberMe ID (refresh token) saved. Attempting fast login.
[81] [TaskLogger][Accounts - Startup] Fast login error: -1 |
Sending player back to Login screen.
[86] [AssetBundles] GET manifest pointer from https://assets.mtgarena.wizards.com/External_2024.33.70.5061.1049592-windows.mtga ...
[87] [TaskLogger]Unexpected HTTP response when fetching manifest pointer file from https://assets.mtgarena.wizards.com/External_2024.33.70.5061.1049592-windows.mtga: (-1)
[88] ArgumentNullException: Value cannot be null.

PC version only

Same issue, can't play the game anymore and nothing seems to work.

HELLO, we need all a Solution!!!

I have the same problem here!

also getting Error Updating Data - Please check your connection and try again - 2024.33.70.5061 patch, started 01/26

I have also had this issue for a few days now. I have tried rebooting, restarting and reinstalling the client to no avail. My internet connection is working fine. I am able to play via my iPad however my PC version will not load.

Same here. I have been unable to play for days now. Reinstalling, flushing DNS, resetting sockets, runnning different client, using a VPN, none of it does anything, the game just will not connect to the server.

It's like it is not even trying, it just immediately displays the error after half a millisecond.

PC version only

Error Updating Data
I don't know how to solve it
It's been three days ago

I have started getting this error since the latest update on PC. I am unable to get past this error. My internet connection is fine.

Same issue on PC after the Jan 26th update. It's ok on mobile. I have a draft existing game.

Same issue on PC after the Jan 26th update - I'm on gigabit internet, have tried reinstalling, VPN, et cetera.

My last played game was Historic Brawl, if that's broken anything again.

I have the same issue since last patch yesterday, also tried literally everything.

I contacted support, they said they have no solution.

This is now happening to me after updating the client. It's happening through Steam, standalone client, and mobile.

I've had this problem for three days now

If I had to guess, it seems to have something to do with the renaming of Historic Brawl to just Brawl. Anyone else play Historic Brawl as their last game before the update?