Steam Controller and KDE Plasma's "Allow using as pointer and keyboard" can break input and crash the Steam client

steamopen appid 2026Window managerSteam controller

ValveSoftware/steam-for-linux#13266 · opened 2026-05-27 by notpentadactyl · updated 2026-08-21 · 3 comments · github · game page · search this game

Nnotpentadactyl 2026-05-27 github

Your system information

Steam client version (build number or date): 1779479049
Distribution (e.g. Ubuntu): CachyOS
Opted into Steam client beta?: Yes
Have you checked for system updates?: Yes
GPU: Nvidia

Please describe your issue in as much detail as possible:

Using the new Steam Controller together with the "Allow using as pointer and keyboard" setting¹ toggled on in KDE Plasma (6.6.5 as of this reporting) seems to (sometimes) break² controller input and can crash games and the Steam client³.

¹:

²: break meaning double/ghost or no input for some buttons.

³: the client gets stuck/hangs (more noticeable in Big Picture mode) and crashes.

I did find some issues on the KDE bug tracker that might be related:

Allow using as pointer and keyboard can break games: https://bugs.kde.org/show_bug.cgi?id=520312
Using gamepad as pointer/keyboard option breaks Steam Input in-game: https://bugs.kde.org/show_bug.cgi?id=515994

Plasma and Steam are probably fighting over the controller and there might be some race conditions (?), but it is hard to tell for me.

Using Big Picture mode seems to make the controller work a lot better if the controller was turned on before launching the game at least, but it can and will break too at some point.

The only fix that I found is to disable "Allow using as pointer and keyboard".

Steps for reproducing this issue:

Turn on "Allow using as pointer and keyboard" (see image "¹" above).
Launch a game like "DRAGON QUEST MONSTERS: The Dark Prince" (2175540) which reliable gives me double input (see "²" above).
The Steam client might crash (unreliable reproduce).

Nnotpentadactyl 2026-05-27 github

Note: I now crashed the Steam client even with this option toggled off. Which might point to "Allow using as pointer and keyboard" to not cause the client from crashing, but just cause the double/no input.

Steam was running, I turned the controller on, pressed the Steam button to focus the client and once again to go to Big Picture mode, started my game and the client got stuck (log below).

Assertion Failed: CSteamEngine::BMainLoop appears to have stalled > 15 seconds without event signalled was printed while the client was still in some kind of working state, but the game was "delayed from launching", which you could not cancel, after some time it crashed:

[2026-05-27 21:16:33] pid 14454 != 14453, skipping destruction (fork without exec?)
[2026-05-27 21:16:33] Game Recording - game stopped [gameid=1617400]
[2026-05-27 21:16:33] Removing process 14527 for gameID 1617400
[2026-05-27 21:16:33] Removing process 14509 for gameID 1617400
[2026-05-27 21:16:33] Removing process 14482 for gameID 1617400
[2026-05-27 21:16:33] Removing process 14475 for gameID 1617400
[2026-05-27 21:16:33] Removing process 14470 for gameID 1617400
[2026-05-27 21:16:33] Removing process 14461 for gameID 1617400
[2026-05-27 21:16:33] Removing process 14458 for gameID 1617400
[2026-05-27 21:16:33] Removing process 14456 for gameID 1617400
[2026-05-27 21:16:33] Removing process 14453 for gameID 1617400
[2026-05-27 21:16:33] Removing process 14452 for gameID 1617400
[2026-05-27 21:16:33] Removing process 14451 for gameID 1617400
[2026-05-27 21:16:33] Removing process 14450 for gameID 1617400
[2026-05-27 21:16:33] Removing process 14348 for gameID 1617400
[2026-05-27 21:16:33] Removing process 14347 for gameID 1617400
[2026-05-27 21:16:33] Removing process 14346 for gameID 1617400
[2026-05-27 21:16:45] reaping pid: 14700 -- gameoverlayui
[2026-05-27 21:17:55] ntsync: up and running.
[2026-05-27 21:17:55] chdir "/home/user/Games/DDON/"
[2026-05-27 21:17:55] ERROR: ld.so: object '/home/user/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
[2026-05-27 21:17:55] ERROR: ld.so: object '/home/user/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
[2026-05-27 21:17:55] ERROR: ld.so: object '/home/user/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
[2026-05-27 21:17:55] ERROR: ld.so: object '/home/user/.local/share/Steam/ubuntu12_64/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS64): ignored.
[2026-05-27 21:17:55] ERROR: ld.so: object '/home/user/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
[2026-05-27 21:17:55] ERROR: ld.so: object '/home/user/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
[2026-05-27 21:17:55] src/tier1/KeyValues.cpp (3120) : Assertion Failed: Error while parsing text KeyValues for resource controller_mappings
[2026-05-27 21:17:55] src/tier1/KeyValues.cpp (3120) : Assertion Failed: Error while parsing text KeyValues for resource controller_mappings
[2026-05-27 21:17:55] ntsync: up and running.
[2026-05-27 21:17:56] [obs-vkcapture] Init Vulkan 1.5.5 (64bit)
[2026-05-27 21:17:56] Fossilize INFO: Overriding serialization path: "/home/user/.local/share/Steam/shader_cache_temp_dir_d3d11_64/fozpipelinesv6/steamapprun_pipeline_cache".
[2026-05-27 21:17:56] [obs-vkcapture] Init Vulkan 1.5.5 (64bit)
[2026-05-27 21:17:57] [obs-vkcapture] Init Vulkan 1.5.5 (64bit)
[2026-05-27 21:18:12] src/clientdll/steamengine.cpp (2838) : Assertion Failed: CSteamEngine::BMainLoop appears to have stalled > 15 seconds without event signalled
[2026-05-27 21:18:12] src/clientdll/steamengine.cpp (2838) : Assertion Failed: CSteamEngine::BMainLoop appears to have stalled > 15 seconds without event signalled
[2026-05-27 21:20:55] src/common/pipes.cpp (900) : fatal stalled cross-thread pipe.
[2026-05-27 21:20:55] src/common/pipes.cpp (900) : fatal stalled cross-thread pipe.
[2026-05-27 21:20:57] src/common/pipes.cpp (900) : fatal stalled cross-thread pipe.
[2026-05-27 21:20:57] src/common/pipes.cpp (900) : fatal stalled cross-thread pipe.
[2026-05-27 21:20:57] src/common/pipes.cpp (900) : Fatal assert; application exiting
[2026-05-27 21:20:57] src/common/pipes.cpp (900) : Fatal assert; application exiting
[2026-05-27 21:20:57] 05/27 21:20:57 minidumps folder is set to /tmp/dumps
[2026-05-27 21:20:57] 05/27 21:20:57 Init: Installing breakpad exception handler for appid(wine-preloader)/version(1.0)/tid(17645)
[2026-05-27 21:20:57] assert_20260527212057_3.dmp[18350]: Uploading dump (out-of-process)
[2026-05-27 21:20:57] /tmp/dumps/assert_20260527212057_3.dmp
[2026-05-27 21:20:57] _ExitOnFatalAssert
[2026-05-27 21:20:57] pid 17647 != 17646, skipping destruction (fork without exec?)
[2026-05-27 21:20:59] assert_20260527212057_3.dmp[18350]: Finished uploading minidump (out-of-process): success = yes
[2026-05-27 21:20:59] assert_20260527212057_3.dmp[18350]: response: Discarded=1
[2026-05-27 21:20:59] assert_20260527212057_3.dmp[18350]: file ''/tmp/dumps/assert_20260527212057_3.dmp'', upload yes: ''Discarded=1''
[2026-05-27 21:20:59] pid 18350 != 18349, skipping destruction (fork without exec?)
[2026-05-27 21:21:05] assert_20260527212105_246.dmp[18380]: Uploading dump (out-of-process)
[2026-05-27 21:21:05] /tmp/dumps/assert_20260527212105_246.dmp
[2026-05-27 21:21:06] /home/user/.local/share/Steam/steam.sh: line 966:  6574 Segmentation fault         (core dumped) "$STEAMROOT/$STEAMEXEPATH" "$@"
[2026-05-27 21:21:06] assert_20260527212105_246.dmp[18380]: Finished uploading minidump (out-of-process): success = yes
[2026-05-27 21:21:06] assert_20260527212105_246.dmp[18380]: response: CrashID=bp-c0f6b02c-c995-4c8b-b3c3-0eee42260527
[2026-05-27 21:21:06] assert_20260527212105_246.dmp[18380]: file ''/tmp/dumps/assert_20260527212105_246.dmp'', upload yes: ''CrashID=bp-c0f6b02c-c995-4c8b-b3c3-0eee42260527''

This is a non-steam game that was added to steam (works fine with other controllers, also sometimes works fine with the Steam Controller).

As the log shows: [2026-05-27 21:17:56] [obs-vkcapture] Init Vulkan 1.5.5 (64bit) I do use env OBS_VKCAPTURE=1 %command%, unsure if this could have an effect?

Nnotpentadactyl 2026-06-02 github

I just had another Steam client crash because I forgot to turn the controller off before launching Path of Exile 2.

Here are the CrashIDs:

[2026-06-02 18:10:53] assert_20260602181051_59.dmp[10146]: response: CrashID=bp-f6b48897-c8d2-462b-b26b-031af2260602
[2026-06-02 18:10:53] assert_20260602181051_59.dmp[10146]: file ''/tmp/dumps/assert_20260602181051_59.dmp'', upload yes: ''CrashID=bp-f6b48897-c8d2-462b-b26b-031af2260602''
[2026-06-02 18:11:12] assert_20260602181111_62.dmp[10173]: response: CrashID=bp-5fed52c3-2b17-4f93-a223-af1ea2260602
[2026-06-02 18:11:12] assert_20260602181111_62.dmp[10173]: file ''/tmp/dumps/assert_20260602181111_62.dmp'', upload yes: ''CrashID=bp-5fed52c3-2b17-4f93-a223-af1ea2260602''

edit: this is on the stable client (1780352834), switched from beta because I hoped for improvements.

JjavaJake 2026-08-21 github

I'm experiencing the same problem. Same as you, it only appears if the Steam controller is turned on. Strangely, usually a killall -SEGV steam, giving Steam a bit to clean up, then starting Steam again works around the the issue.

I am also using CachyOS and KDE.

Launch lines

OBS_VKCAPTURE=1 %command%x1 2026-05