Compatibility tool and version

• Proton Experimental (tested)
• GE-Proton11-5-x86_64 (tested, same result)

Public bug report

Not yet filed / linked

System information

• GPU: NVIDIA GeForce RTX 4070 SUPER, driver 610.57.04
• Kernel: 6.19.10-300.fc44.x86_64 (Fedora 44)
• Wine (via GE-Proton11-5): 11.0 (Staging)

I'm reporting a bug

• [ ] The game runs fine, but has minor issues

Actually more accurately: the game/launcher does not run at all — it fails during the Paradox Launcher v2 prerequisite install step before the game can start.

Steps for reproducing this issue

1. Own Victoria 3 (appid 529340) on Steam.
2. Force the compatibility tool to Proton Experimental or GE-Proton11-5 (Properties → Compatibility).
3. Launch the game from Steam.
4. The "Paradox Launcher v2 Prerequisite Setup" dialog appears, runs briefly, then fails with:
   Setup Failed — 0x80091007 - Call failed.

Log excerpt (from launcher-installer.log inside the prefix)

[01F8:0294]i338: Acquiring package: VC_REDIST_X64, payload: VC_REDIST_X64, download from: https://download.visualstudio.microsoft.com/download/pr/1754ea58-11a6-44ab-a262-696e194ce543/3642E3F95D50CC193E4B5A0B0FFBF7FE2C08801517758B4C8AEB7105A091208A/VC_redist.x64.exe
[0248:0290]e000: Error 0x80091007: Hash mismatch for path: C:\ProgramData\Package Cache\.unverified\VC_REDIST_X64,
  expected: 84C61FADF8CD38016FB7632969B3ACE9E54B763A
  actual:   5935B69F5138AC3FBC33813C74DA853269BA079F910936AEFA95E230C6092B92F6225BFFB594E5DD35FF29BF260E4B35F91ADEDE90FDF5F062030D8666FD0104
[0248:0290]e000: Error 0x80091007: Failed to verify hash of payload: VC_REDIST_X64

Note the digest lengths: expected is 40 hex characters (20 bytes → consistent with SHA-1), while actual is 128 hex characters (64 bytes → consistent with SHA-512). This isn't a corrupted-download or stale-cache scenario (the "actual" value would still be a same-length SHA-1 digest, just a different value, if the payload itself had changed) — the bootstrapper appears to be hashing the downloaded payload with a different algorithm than the one the manifest's expected hash was computed with. This points to an algorithm-selection bug in Wine's bcrypt/CNG hashing implementation as invoked by this WiX Burn bootstrapper, rather than a bad download.

What I already tried

• Retried with both Proton Experimental and GE-Proton11-5 — identical failure, identical hash values, on both.
• Deleted compatdata/529340 and let Steam rebuild the prefix from scratch — same failure.
• Pre-installed the VC++ 2015-2022 x86 and x64 redistributables into the prefix directly via protontricks 529340 vcrun2022 (bypassing the bootstrapper's own install path entirely) — the bootstrapper still re-downloads and re-verifies VC_REDIST_X64 on its own and fails at the same hash-verification step regardless, since it doesn't check pre-existing installs before re-verifying its bundled payload.

Notes

• The native Linux build of Victoria 3 runs fine and does not hit this code path at all (it doesn't use this Windows launcher-installer).
• This may not be Victoria-3-specific — Paradox Launcher v2's WiX Burn bootstrapper is shared across their catalog (EU4, Cities: Skylines II, Age of Wonders 4, Imperator: Rome, etc.), so this could reproduce on any Paradox title using launcher-v2 build 2026.9 under current Proton/Wine.