All Discussions > Steam Forums > Help and Tips > Topic Details
Trymado 22 Oct @ 1:21pm
Persistent “TypeError: SteamClient.System…” notification when launching Session on Steam
Hi everyone,

I’ve been dealing with a strange issue on my Steam Deck and I can’t seem to find anyone else having the same problem.
Every time I launch a Steam session — whether in Desktop Mode or Gaming Mode — I get a notification saying:

TypeError: SteamClient.System.RegisterForOn...

It always appears right when I select my Steam session (not immediately on startup, but when Steam itself begins loading).

Here’s what I’ve already tried:

Reinstalling and removing CSS Loader / Decky Loader plugins


Updating KDE and SteamOS to the latest stable version

Checking logs via journalctl -f (the TypeError pops up, but no critical errors appear)

What’s confusing is that the notification still appears even after uninstalling CSS Loader, so something seems to persist or be triggered at Steam startup.

Same error on Desktop mode

Thanks

Image: https://ibb.co/RkSXkBrf

Journal log:

oct. 21 14:39:08 steamdeck steam[15587]: Desktop state changed: desktop: { pos: 0, 0 size: 1280, 800 } primary: { pos: 0, 0 size: 1280, 800 }
oct. 21 14:39:08 steamdeck steam[15587]: Caching cursor image for , size 32x32, serial 332, cache size = 0
oct. 21 14:39:08 steamdeck PluginLoader[1394]: [CSS_Loader] Connected to tab: Steam
oct. 21 14:39:08 steamdeck PluginLoader[1394]: [CSS_Loader] Disconnected from tab: Se connecter à Steam
oct. 21 14:39:08 steamdeck kernel: input: Microsoft X-Box 360 pad 0 as /devices/virtual/input/input69
oct. 21 14:39:08 steamdeck rtkit-daemon[1490]: Successfully made thread 16301 of process 15618 owned by '1000' high priority at nice level -10.
oct. 21 14:39:08 steamdeck rtkit-daemon[1490]: Supervising 9 threads of 4 processes of 1 users.
oct. 21 14:39:08 steamdeck sddm-helper-start-x11user[8233]: "(II) config/udev: Adding input device Microsoft X-Box 360 pad 0 (/dev/input/js0)\n(II) No input driver specified, ignoring this device.\n(II) This device may have been added with another device file.\n"
oct. 21 14:39:08 steamdeck kded6[8348]: Registering ":1.273/org/ayatana/NotificationItem/steam" to system tray
oct. 21 14:39:08 steamdeck sddm-helper-start-x11user[8233]: "(II) config/udev: Adding input device Microsoft X-Box 360 pad 0 (/dev/input/event21)\n"
oct. 21 14:39:08 steamdeck sddm-helper-start-x11user[8233]: "(II) No input driver specified, ignoring this device.\n(II) This device may have been added with another device file.\n"
oct. 21 14:39:08 steamdeck PluginLoader[1394]: [CSS_Loader] Connected to tab: notificationtoasts_undefined_desktop
oct. 21 14:39:09 steamdeck steam[15587]: i386-linux-gnu-capsule-capture-libs: warning: Dependencies of /usr/lib32/libMangoHud.so not found, ignoring: Missing dependencies: Could not find "libxkbcommon.so.0" in LD_LIBRARY_PATH "/home/deck/.local/share/Steam/ubuntu12_32:/home/deck/.local/share/Steam/ubuntu12_32/panorama:/usr/lib32:/usr/lib/perf:/usr/lib", ld.so.cache, DT_RUNPATH or fallback /lib:/usr/lib
oct. 21 14:39:09 steamdeck PluginLoader[1394]: [CSS_Loader] Connected to tab:
oct. 21 14:39:09 steamdeck PluginLoader[1394]: [CSS_Loader] Connected to tab: Steam Root Menu
oct. 21 14:39:09 steamdeck PluginLoader[1394]: [CSS_Loader] Failed to connect to tab with id 19A06A2C460D0DDE9E4FD5EC7596B2B6
oct. 21 14:39:10 steamdeck PluginLoader[1394]: [CSS_Loader] Failed to connect to tab with id 1209DE6243A09EEACFE201A4D435DAE2
oct. 21 14:39:10 steamdeck PluginLoader[1394]: [CSS_Loader] Failed to connect to tab with id 3D1A097F9E822D34F203808C89B98BB8
oct. 21 14:39:10 steamdeck steam[15587]: ProtonFixes[16456] WARN: [CONFIG]: Parent directory "/home/deck/.config/protonfixes" does not exist. Abort.
oct. 21 14:39:10 steamdeck steam[15587]: ProtonFixes[16456] WARN: Skipping fix execution. We are probably running an unit test.
oct. 21 14:39:10 steamdeck steam[15587]: fsync: up and running.
oct. 21 14:39:10 steamdeck PluginLoader[1394]: [CSS_Loader] Failed to connect to tab with id 8735E421B090348F8CC5D8CFDFF669D9
oct. 21 14:39:10 steamdeck PluginLoader[1394]: [CSS_Loader] Failed to connect to tab with id BA99C726763E020C6ED3A9F353183154
oct. 21 14:39:11 steamdeck PluginLoader[1394]: [CSS_Loader] Connected to tab: Help Root Menu
oct. 21 14:39:11 steamdeck PluginLoader[1394]: [CSS_Loader] Connected to tab: Notifications Menu
oct. 21 14:39:11 steamdeck PluginLoader[1394]: [CSS_Loader] Connected to tab: Games Root Menu
oct. 21 14:39:11 steamdeck PluginLoader[1394]: [CSS_Loader] Connected to tab: View Root Menu
oct. 21 14:39:11 steamdeck PluginLoader[1394]: [CSS_Loader] Connected to tab: Friends Root Menu
oct. 21 14:39:11 steamdeck PluginLoader[1394]: [CSS_Loader] Connected to tab: Notifications Menu
oct. 21 14:39:11 steamdeck PluginLoader[1394]: [CSS_Loader] Connected to tab: Store Supernav
oct. 21 14:39:11 steamdeck PluginLoader[1394]: [CSS_Loader] Connected to tab: Library Supernav
oct. 21 14:39:12 steamdeck PluginLoader[1394]: [CSS_Loader] Connected to tab: Profile Supernav
oct. 21 14:39:12 steamdeck sddm-helper-start-x11user[8233]: "(II) AMDGPU(0): EDID vendor \"VLV\", prod id 12291\n"
oct. 21 14:39:12 steamdeck sddm-helper-start-x11user[8233]: "(II) AMDGPU(0): Using hsync ranges from config file\n(II) AMDGPU(0): Using vrefresh ranges from config file\n(II) AMDGPU(0): Printing DDC gathered Modelines:\n(II) AMDGPU(0): Modeline \"800x1280\"x0.0 133.20 800 1076 1084 1128 1280 1289 1290 1312 +hsync +vsync (118.1 kHz eP)\n"
oct. 21 14:39:12 steamdeck sddm-helper-start-x11user[8233]: "(II) AMDGPU(0): EDID vendor \"VLV\", prod id 12291\n(II) AMDGPU(0): Using hsync ranges from config file\n(II) AMDGPU(0): Using vrefresh ranges from config file\n(II) AMDGPU(0): Printing DDC gathered Modelines:\n"
oct. 21 14:39:12 steamdeck sddm-helper-start-x11user[8233]: "(II) AMDGPU(0): Modeline \"800x1280\"x0.0 133.20 800 1076 1084 1128 1280 1289 1290 1312 +hsync +vsync (118.1 kHz eP)\n"
oct. 21 14:39:12 steamdeck steam[15587]: Fossilize INFO: Overriding serialization path: "/home/deck/.local/share/Steam/shader_cache_temp_dir_d3d11_64/fozpipelinesv6/steamapprun_pipeline_cache".
oct. 21 14:39:14 steamdeck PluginLoader[1394]: [CSS_Loader] Disconnected from tab: notificationtoasts_undefined_desktop
oct. 21 14:39:15 steamdeck PluginLoader[1394]: [CSS_Loader] Connected to tab: Community Supernav
oct. 21 14:39:15 steamdeck PluginLoader[1394]: [CSS_Loader] Connected to tab: Account Menu
oct. 21 14:39:15 steamdeck steam[15587]: i386-linux-gnu-capsule-capture-libs: warning: Dependencies of /usr/lib32/libMangoHud.so not found, ignoring: Missing dependencies: Could not find "libxkbcommon.so.0" in LD_LIBRARY_PATH "/home/deck/.local/share/Steam/ubuntu12_32:/home/deck/.local/share/Steam/ubuntu12_32/panorama:/usr/lib32:/usr/lib/perf:/usr/lib", ld.so.cache, DT_RUNPATH or fallback /lib:/usr/lib
oct. 21 14:39:16 steamdeck steam[15587]: ProtonFixes[16755] WARN: [CONFIG]: Parent directory "/home/deck/.config/protonfixes" does not exist. Abort.
oct. 21 14:39:16 steamdeck steam[15587]: ProtonFixes[16755] WARN: Skipping fix execution. We are probably running an unit test.
oct. 21 14:39:16 steamdeck steam[15587]: fsync: up and running.
oct. 21 14:39:18 steamdeck sddm-helper-start-x11user[8233]: "(II) AMDGPU(0): EDID vendor \"VLV\", prod id 12291\n(II) AMDGPU(0): Using hsync ranges from config file\n(II) AMDGPU(0): Using vrefresh ranges from config file\n"
oct. 21 14:39:18 steamdeck sddm-helper-start-x11user[8233]: "(II) AMDGPU(0): Printing DDC gathered Modelines:\n(II) AMDGPU(0): Modeline \"800x1280\"x0.0 133.20 800 1076 1084 1128 1280 1289 1290 1312 +hsync +vsync (118.1 kHz eP)\n"
oct. 21 14:39:18 steamdeck sddm-helper-start-x11user[8233]: "(II) AMDGPU(0): EDID vendor \"VLV\", prod id 12291\n(II) AMDGPU(0): Using hsync ranges from config file\n(II) AMDGPU(0): Using vrefresh ranges from config file\n(II) AMDGPU(0): Printing DDC gathered Modelines:\n"
oct. 21 14:39:18 steamdeck sddm-helper-start-x11user[8233]: "(II) AMDGPU(0): Modeline \"800x1280\"x0.0 133.20 800 1076 1084 1128 1280 1289 1290 1312 +hsync +vsync (118.1 kHz eP)\n"
oct. 21 14:39:19 steamdeck steam[15587]: Fossilize INFO: Overriding serialization path: "/home/deck/.local/share/Steam/shader_cache_temp_dir_d3d12_64/fozpipelinesv6/steamapprun_pipeline_cache".
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Showing 1-4 of 4 comments
Assistant 22 Oct @ 11:05pm 
The error happens because some Decky or CSS Loader plugin code is still running even after uninstalling. Remove all related config files, reinstall Decky cleanly, and clear Steam’s cache to stop the leftover script from loading.
#1
Trymado 24 Oct @ 10:48am 
Issue:
After updating SteamOS, I kept getting a TypeError: SteamClient.System error in notifications when launching Discover or Steam.

Root Cause:
The error was caused by the DiscordStatue plugin in DeckyLoader. This plugin became incompatible with the latest SteamOS/DeckyLoader version, triggering the TypeError at startup. It was not a SteamOS or Discover issue.

Resolution:

Backup your DeckyLoader plugins.

Uninstall or “wipe” DeckyLoader to reset its environment.

Reinstall DeckyLoader without restoring plugins initially.

Test Steam/Discover to ensure no error appears.

Restore plugins one by one, testing Steam/Discover each time.

Identify the plugin causing the error—in this case, DiscordStatue.

Leave the problematic plugin disabled or remove it until an updated, compatible version is released.

Outcome:
After removing DiscordStatue, Steam and Discover launched without any errors. All other plugins continued to work normally.

thx for help
#2
Assistant 24 Oct @ 10:57am 
Originally posted by Trymado:
Issue:
After updating SteamOS, I kept getting a TypeError: SteamClient.System error in notifications when launching Discover or Steam.

Root Cause:
The error was caused by the DiscordStatue plugin in DeckyLoader. This plugin became incompatible with the latest SteamOS/DeckyLoader version, triggering the TypeError at startup. It was not a SteamOS or Discover issue.

Resolution:

Backup your DeckyLoader plugins.

Uninstall or “wipe” DeckyLoader to reset its environment.

Reinstall DeckyLoader without restoring plugins initially.

Test Steam/Discover to ensure no error appears.

Restore plugins one by one, testing Steam/Discover each time.

Identify the plugin causing the error—in this case, DiscordStatue.

Leave the problematic plugin disabled or remove it until an updated, compatible version is released.

Outcome:
After removing DiscordStatue, Steam and Discover launched without any errors. All other plugins continued to work normally.

thx for help
Ai?
#3
Trymado 24 Oct @ 11:57am 
Not AI, i'm french and my english is very bad, chatgpt has translate my solution in English ^^
Last edited by Trymado; 24 Oct @ 12:12pm
#4
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All Discussions > Steam Forums > Help and Tips > Topic Details
Date Posted: 22 Oct @ 1:21pm
Posts: 4
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