Proton Mail desktop crashes at startup: EXCEPTION_ACCESS_VIOLATION at Proton Mail.exe+0x2c730ca on Windows 11 24H2

Summary

Proton Mail desktop app crashes deterministically at startup on Windows 11 24H2. Crash is version-independent (reproduced on 1.13.0, 1.4.0, and 1.7.1 — all three). GPU driver updates did not help.

Environment

Component	Value
OS	Windows 11 Pro 24H2 (Build 26200.8328)
CPU	Intel Core i7-8700 (Coffee Lake, 6C/12T, 3.20 GHz)
iGPU	Intel UHD Graphics 630
dGPU	NVIDIA GeForce RTX 2060 (driver 32.0.16.1088, Game Ready 22-07-2026)
Motherboard	MSI H310M PRO-M2 PLUS (MS-7C08)
RAM	16 GB
Working	Proton Pass 1.36.1 (with GPU flags), Discord, CurseForge

Crash Signature

ExceptionCode:    EXCEPTION_ACCESS_VIOLATION (0xc0000005)
ExceptionAddress: 0x<base> + 0x2c730ca
Module:           Proton Mail.exe (172.1 MB binary)
Section:          .text
Registers:        Rax=2, Rbx=0, Rcx=0, Rdx=4, Rbp=0  (null pointer dereference)
Consistent:       YES — same offset on every crash, every version (1.4.0, 1.7.1)

What Proton Mail reports about GPU (from main.log)

{
  "gpuDevice": [
    {"deviceString": "NVIDIA GeForce RTX 2060", "active": false},
    {"deviceString": "Intel(R) UHD Graphics 630", "active": false},
    {"deviceString": "Microsoft Basic Render Driver", "active": false}
  ],
  "glImplementationParts": "(gl=none,angle=none)",
  "vulkanVersion": "Not supported",
  "inProcessGpu": true
}

All 3 GPUs report active: false. App crashes during loadURL https://mail.proton.me/ in renderer initialization.

Versions Tested

Version	Result	Binary size
1.13.0 (original)	Crash at offset 0x242d60a	208 MB
1.4.0 (forced via Squirrel)	Crash at offset 0x2c730ca	172 MB
1.7.1 (latest, forced via Squirrel)	Crash at offset 0x2c730ca	172 MB

Steps That Did NOT Fix It

1. GPU flags: --disable-gpu --disable-gpu-sandbox --disable-software-rasterizer --no-sandbox --disable-d3d11 --use-gl=disabled --in-process-gpu --disable-features=Vulkan,UseSkiaRenderer
2. Wipe Crashpad, Cache, GPUCache, Local Storage, Session Storage, blob_storage, config.json from Roaming
3. Forced Squirrel updates: 1.13.0 → 1.4.0 → 1.7.1 (all crash with same offset)
4. NVIDIA GeForce driver update (32.0.16.1088, latest)
5. Intel DSA — reports "up to date" but Intel UHD 630 driver remains 31.0.101.2115 from 2022-11-16 (couldn't find newer standalone)

Workaround

Use Proton Mail via mail.proton.me in browser. Works perfectly. Proton Pass desktop, Discord, CurseForge all work with various GPU-disable flag combinations.

Hypothesis

Crash at offset 0x2c730ca in .text section suggests:

• Proton Mail tries to bind a GPU context during renderer init (loadURL)
• Binding fails because all GPUs report active: false
• null pointer / invalid handle dereferenced during error path
• Likely a CHECK() or DCHECK() macro not designed for "no GPU available" case

Minidumps

Crashpad dumps preserved at:
C:\Users\rainb\AppData\Roaming\Proton Mail\Crashpad\reports\

3 dumps available (34 MB each):

• e936f1ea-a98f-46b9-a551-8b2285708b87.dmp (2026-08-07 23:25:42)
• 8f516d55-1d12-4a9a-be31-99e9a3a3af81.dmp (2026-08-07 21:51:16)
• 175ce38a-d974-4696-b5d6-637807b311cd.dmp (2026-08-07 21:54:42)

User willing to provide dumps via Dropbox / similar if needed.

Requested Fix

1. Better handling of "no GPU active" case (e.g., fallback to SwiftShader / LLVMpipe / software rendering)
2. Or: allow explicit GPU disabling via app config (similar to Discord's chromiumSwitches in settings.json)
3. Investigate why all 3 GPUs report active: false on this configuration

User Impact

• App completely unusable on desktop since 2026-07-22 (last successful use)
• Forced to use web client as workaround
• Affects Proton Mail only — Proton Pass, Discord, CurseForge work fine on same system

Start with the preserved Crashpad dumps and main.log GPU fields, then reproduce startup on Windows 11 24H2 while observing renderer initialization at loadURL https://mail.proton.me/. Compare the affected versions and verify whether the fix prevents the deterministic crash when all GPUs report active: false; the issue does not identify a source file or test.