We can't connect you to the Blizzard patch service. Please check your internet connection and try again. Error Code: BLZBNTBTS00000028

[jonx]

Hello,

thanks for building this, I can't wait for it to work. I'm on a macbook air M5 and my internet connection works.

Let me know if you need more info or if I can help in any way. Thanks

[jonx]

I investigated and was able to solve the problem:

1) For the developer

Environment
D4Mac 0.2.2 (build 5)
macOS 26.5.1 (25F80), Apple Silicon (M5)
Bundled runtime: wine-11.0, x86_64 (Rosetta)

Symptom
On a fully-online machine, selecting Battle.net-Setup.exe runs the bootstrapper, which fails in ~80 ms with BLZBNTBTS00000028 ("can't connect to the Blizzard patch service"). D4Mac then reports it couldn't find an installed Battle.net.

Setup log:
[TactProduct] Downloading from version service: https://us.version.battle.net/bts/versions
[TactProduct] Failed to download: https://us.version.battle.net/bts/versions
[Main] BootstrapperException(code=BLZBNTBTS00000028)

Root cause — it's TLS, not networking. The bundled Wine has no gnutls, so it has no HTTPS support. With WINEDEBUG=+winsock the very first thing logged at bootstrapper start is:
err:winediag:gnutls_process_attach failed to load libgnutls, no support for encryption
err:winediag:process_attach Failed to load libgnutls, secure connections will not be available.
err:secur32:SECUR32_initSchannelSP no schannel support, expect problems
The version service is HTTPS, so the request dies instantly. Confirmed there is no libgnutls* anywhere in Contents/SharedSupport/Wine/, and bcrypt.so/crypt32.so dlopen libgnutls.30.dylib (among other names) which isn't present.

Why some users don't hit it: BNetLauncher.environment sets DYLD_FALLBACK_LIBRARY_PATH = <lib/external>:/usr/local/lib:/usr/lib. Anyone who happens to have an x86_64 libgnutls.30.dylib in /usr/local/lib (e.g. a leftover Intel Homebrew) silently works; everyone else fails. That likely explains inconsistent "can't connect" reports.

Verified fix on my side: installed x86_64 gnutls into /usr/local/lib (arch -x86_64 brew install gnutls). The bootstrapper then passes the version service and reaches STATE_INSTALL_CLIENT / the install splash. No other change.

Suggested real fix: bundle gnutls + its dependency closure (nettle/libhogweed, gmp, libtasn1, p11-kit, libidn2, libunistring, gettext/libintl) as x86_64 dylibs inside Contents/SharedSupport/Wine/lib/external/ (already on the DYLD fallback path), with install_name_tool/rpath fixups so they're self-contained — same approach CrossOver/WineKegworks use. Without it the app can't do any HTTPS, which breaks login/patching for users on a clean machine.

Secondary (separate) issue: the bundle is also missing libMoltenVK.dylib — err:vulkan:vulkan_init_once Failed to load libMoltenVK.dylib. Non-fatal for install (GPTK D3DMetal is the primary backend and libd3dshared.dylib/d3d12.dll are present), but worth bundling too for the Vulkan fallback path.

2) For other users (workaround until it's fixed)

D4Mac: stuck on "can't connect to the Blizzard patch service" (BLZBNTBTS00000028) even though you're online?

It's not your internet. D4Mac's bundled Wine is missing its TLS library (libgnutls), so it can't make any HTTPS connection — and Battle.net's installer needs HTTPS. The fix is to drop a TLS library where D4Mac's Wine already looks for it.

Important: D4Mac's Wine is x86_64 (Intel, via Rosetta), so you need the Intel build of gnutls, installed via an Intel Homebrew at /usr/local (not the Apple-Silicon one at /opt/homebrew).

1. Rosetta (if you don't have it)

softwareupdate --install-rosetta --agree-to-license

2. Intel Homebrew (skip if /usr/local/bin/brew already exists)

arch -x86_64 /bin/bash -c
"$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

3. Install the Intel (x86_64) gnutls

HOMEBREW_NO_AUTO_UPDATE=1 arch -x86_64 /usr/local/bin/brew install gnutls

4. Verify it landed and is x86_64

file -L /usr/local/lib/libgnutls.30.dylib # should say ... x86_64
Then just re-run D4Mac and install Battle.net again — it'll get past the error and show the real installer. (Leave the library in place; removing it brings the error back.)

Tested on macOS 26 (Tahoe), Apple Silicon, D4Mac 0.2.2.

[jonx]

Ha, I just noticed that there is a PR for that already: #4

[jonx]

My experience and tips on how to get the game to run: https://www.reddit.com/r/macgaming/comments/1uaxxj0/how_i_got_diablo_iv_running_on_an_m5_macbook_air/