An update to Battle.net broke Wine support.
You can expect a Wine-GE update soon but in the meantime, you can apply this workaround.
Open Battle.net's configuration in Lutris and set the following environment variable:
WINE_SIMULATE_WRITECOPY=1
@lutris
what is this write copy about?
I don't see any logfile for this bug on the net.
@taketwo to be honest, I have no idea. I noticed the regression with Battle.net, someone suggested that fix and it worked! :D