Unable to launch the game client

I used to play on a Windows-7

I can't launch the game after the Whitemane patch.

When I launch the game using the Blizzard Client, there is a messagebox that says "Downloading game data" (or something like that, I'm not on my gaming machine right now, may edit later to post screenshot), and it wants to download something about 54MB but the download speed is stuck at 0KB/s for more than half an hour.

I can do other stuff online during that time.

It also still receives updates.

I already tried using the Check/Repair Tool to no avail.

I also already checked the Blizzard folder searching for some cache files, I didn't find anything.

Starcraft and Starcraft-2 can launch fine.

It already launched once after the Whitemane patch after I reinstalled the game, but I can't afford to reinstall 20GB again right now.

Does anyone know what may cause this bug?

So, I found the right cache folder to empty, it was in my

AppData\Battle.net\cache

After emptying the whole folder, the game could launch, but no ingame asset could load, no portrait, no hero model... All I could do is chat with my friends and play the tutorials. All other game modes showed the "This game mode is currently disabled" tooltip above the Search button.

It makes sense and I guess I will have to wait for my slowpoke internet to kick in.