protonscr

steamwebhelper: Failed to bind shmem socket on macOS 26.3

steamclosed
ValveSoftware/steam-for-linux#12961 · opened 2026-03-07 by Rumukyu · updated 2026-03-07 · 1 comments · github
RRumukyu 2026-03-07 github

System information:

Steam client version: 1769025840
Distribution: macOS Tahoe 26.3 (25D125)
Opted into Steam client beta?: No
Have you checked for system updates?: Yes
GPU: Apple Silicon (Mac16,12) - ARM-64
Please describe your issue:

Steam fails to launch on macOS Tahoe 26.3. The steamwebhelper process starts but immediately fails with Failed to bind shmem socket in chrome_ipc_server.cpp, causing the UI to hang indefinitely. Steam itself (steam_osx) runs and updates successfully, but the webhelper cannot establish IPC.

Key error from logs/webhelper.txt:
src/common/html/chrome_ipc_server.cpp (97) : !"Failed to bind shmem socket"

Tried without effect: -cef-disable-sandbox, -no-cef-sandbox, -cef-disable-gpu, disabling antivirus (Trend Micro), fresh reinstall of Steam AppBundle.

Steps to reproduce:

Install Steam on macOS Tahoe 26.3
Launch Steam.app
Steam hangs — webhelper fails to bind shmem socket

Kkisak-valve maintainer 2026-03-07 github

Hello @Rumukyu, issues with the Steam for Mac client are out of scope for this issue tracker. Please use Steam Support to reach the larger Steam support team.

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