Ah launchers, don't you just love them? A reoccuring nuisance for Steam Deck and Desktop Linux gaming is that they can and will break and the latest to break (again) is Battle.net. Here's how you can fix it for now.
Firstly, for people just using Proton on Steam Deck and Desktop Linux direct through Steam you can use the bleeding-edge Beta of Proton Experimental. As posted on X (Twitter) by Valve developer Pierre-Loup Griffais:
Initial Battle.net fix has been pushed to the [bleeding-edge] beta branch of Proton Experimental. Timing of mainline Proton Experimental availability is TBD.
How to do that? Find Proton Experimental in your Steam Library and go into its Properties -> Betas -> and select bleeding-edge from the dropdown box.
Another solution that you can try is to use this as a launch option on any Proton version in Steam:
WINE_SIMULATE_WRITECOPY=1 %command%
For people using some form of Wine / Proton in Lutris you can add WINE_SIMULATE_WRITECOPY with a value of 1 as an environment variable in the system options inside a Wine runner you're using.
It can be frustrating when this happens, and it's certainly far from the first time Battle.net has broken along with EA, Ubisoft and other extra launchers. Thankfully this time it's an easy enough sort until it's fixed properly inside Wine and Proton directly.
Update - 17:17 UTC: If you use Wine-GE, the latest Wine-GE-Proton8-25 release has a fix for it.
Quoting: RaabenIt seems Bnet has been breaking fairly often as of late. It's a shame since I remember it being one of the more reliable ones in WINE;I'm not too surprised, honestly, since they're Microsoft-owned now.
Quoting: PenglingQuoting: RaabenIt seems Bnet has been breaking fairly often as of late. It's a shame since I remember it being one of the more reliable ones in WINE;I'm not too surprised, honestly, since they're Microsoft-owned now.
I would highly doubt that's it, I started noticing more around the Shadowlands era.
Quoting: RaabenBlizz always seemed to have an almost official unofficial support a way, remembering back to the never released Linux builds from around Wrath and something else I can't dig up about working around some things when WINE was detected.Sam Lantinga (Loki and SDL creator) worked for Blizzard for quite a while. Not sure if he maybe influenced their approach to Linux and Wine?
Quoting: RaabenI would highly doubt that's it, I started noticing more around the Shadowlands era.I'm afraid I have no idea what that is, but fair enough.
Quoting: PenglingQuoting: RaabenI would highly doubt that's it, I started noticing more around the Shadowlands era.I'm afraid I have no idea what that is, but fair enough.
The 2020 xpac, just using as a time reference
QuoteFor people using some form of Wine / Proton in Lutris you can add WINE_SIMULATE_WRITECOPY with a value of 1 as an environment variable in the system options inside a Wine runner you're using.
Also works great for Bottles too.
<battle.net bottle>->Options->Settings->Compatibility->'Environment Variables'
Prior to this tip. As a work around I opened the file explorer for the bottle and deleted the battle.net.14542 version under the battle.net installation directory.
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