[Linux] Steam In-Game Overlay (gameoverlayui) causes freezes/assertion failure on Alt-Tab across multiple games

steamclosed

ValveSoftware/steam-for-linux#13740 · opened 2026-10-15 by OldNed · updated 2026-10-15 · 1 comments · github

OOldNed 2026-10-15 github

System

OS: Debian GNU/Linux 13 (trixie) x86_64
Kernel: Debian GNU/Linux 13 (trixie) x86_64
CPU: AMD Ryzen 5 5600 (12) @ 4.47 GHz
GPU: Debian GNU/Linux 13 (trixie) x86_64
DE: KDE Plasma 6.3.6
WM: KWin (Wayland)
Memory: 16 GB

Steam client version : 1791918634
Opted into Steam client beta?: No
Have you checked for system updates?: Yes
Steam Logs: steam-logs.tar.gz

Problem:

When alt-tabbing out of games running through Proton (tested across Overwatch, War Thunder, Aimlabs and other games), the game window immediately freezes with sound working. Terminal logs show a SerializedSurface.cpp assertion failure (OnChromePaintBufferClientDisconnect) and subsequent gameoverlayui crashes/minidump generation

src/SerializedSurface.cpp (1437) : Assertion Failed: OnChromePaintBufferClientDisconnect m_mapShMemFD has 1 entries, m_mapChromePaintBufferHandleToData 0 entries.

reaping pid: 11632 -- gameoverlayui
assert_20261015230439_8.dmp[11704]: Uploading dump (out-of-process)

Workaround

Disabling "Enable the Steam Overlay while in-game" in Steam Settings prevents the freezes entirely.

Kkisak-valve maintainer 2026-10-15 github

Hello @OldNed, this issue is already being tracked at #13682. Closing as a duplicate.

Nothing extracted yet.