Screen capture preview disables when OBS Studio is minimized, and can't be re-enabled thereafter without disposing of OBS's configuration directory

[Aaron Rainbolt]

Bug found on Ubuntu Unity 22.10 on my main laptop. I only have one screen, in case it matters.

Steps to reproduce:

1. Install OBS Studio using apt (sudo apt install obs-studio).
2. Open OBS Studio.
3. Proceed through the initial configuration steps.
4. In the Sources pane, click the "+" button, and add a "Screen Capture (XSHM)" source.
5. Click OK in the popup window, then OK again in the next popup window.
6. Minimize the OBS Studio window.
7. Click the OBS Studio icon in the Launcher to bring it back. The preview will be disabled.
8. Click the "Enable Preview" button.

Expected result: The preview should appear.

Actual result: Nothing seems to happen at all.

Notes: Right-clicking in the preview area and clicking "Enable Preview" in the popup menu also fails to cause the preview to appear. It does, however, make the "Enable Preview" button in the middle of the screen appear "active" (which doesn't happen when you first trigger the bug). However, clicking the button again still doesn't bring the preview back, it just makes the button go inactive.

What's really weird is that closing and re-opening OBS Studio does *not* bring the preview back! I have to run "rm -rf .config/obs-studio" in a terminal, and then open OBS Studio again, then re-add my monitor. Then it works.

Here's the output I get in the terminal if I wipe the OBS Studio config directory, then launch OBS from the terminal and reproduce the bug. The line "info: User added source 'Screen Capture (XSHM)' (xshm_input) to scene 'Scene'" is the last line that appears before the bug triggers. Noticeably, no log output is generated when I trigger the bug, nor does anything appear when I do the other steps with clicking the two "Enable Preview" buttons.

debug: Found portal inhibitor
Attempted path: share/obs/obs-studio/locale/en-US.ini
Attempted path: /usr/share/obs/obs-studio/locale/en-US.ini
Attempted path: share/obs/obs-studio/locale.ini
Attempted path: /usr/share/obs/obs-studio/locale.ini
Attempted path: share/obs/obs-studio/themes/Yami.qss
Attempted path: /usr/share/obs/obs-studio/themes/Yami.qss
info: Using EGL/X11
info: CPU Name: 11th Gen Intel(R) Core(TM) i5-1135G7 @ 2.40GHz
info: CPU Speed: 3476.697MHz
info: Physical Cores: 4, Logical Cores: 8
info: Physical Memory: 31883MB Total, 18745MB Free
info: Kernel Version: Linux 5.19.0-29-generic
info: Distribution: "Ubuntu" "22.10"
info: Session Type: x11
info: Window System: X11.0, Vendor: The X.Org Foundation, Version: 1.21.1
info: Qt Version: 5.15.6 (runtime), 5.15.6 (compiled)
info: Portable mode: false
qt.svg: Cannot open file '/usr/share/obs/obs-studio/themes/Dark/Close.svg', because: No such file or directory
qt.svg: Cannot open file '/usr/share/obs/obs-studio/themes/Dark/Close.svg', because: No such file or directory
qt.svg: Cannot open file '/usr/share/obs/obs-studio/themes/Dark/Popout.svg', because: No such file or directory
qt.svg: Cannot open file '/usr/share/obs/obs-studio/themes/Dark/Popout.svg', because: No such file or directory
Attempted path: share/obs/obs-studio/themes/Dark/no_sources.svg
Attempted path: /usr/share/obs/obs-studio/themes/Dark/no_sources.svg
QMetaObject::connectSlotsByName: No matching signal for on_tbar_position_valueChanged(int)
QMetaObject::connectSlotsByName: No matching signal for on_actionShowTransitionProperties_triggered()
QMetaObject::connectSlotsByName: No matching signal for on_actionHideTransitionProperties_triggered()
info: OBS 28.0.1.11-3 (linux)
info: ---------------------------------
info: ---------------------------------
info: audio settings reset:
 samples per sec: 48000
 speakers: 2
 max buffering: 960 milliseconds
 buffering type: dynamically increasing
info: ---------------------------------
info: Initializing OpenGL...
info: Loading up OpenGL on adapter Intel Mesa Intel(R) Xe Graphics (TGL GT2)
info: OpenGL loaded successfully, version 4.6 (Core Profile) Mesa 22.2.1, shading language 4.60
info: ---------------------------------
info: video settings reset:
 base resolution: 1920x1080
 output resolution: 1280x720
 downscale filter: Bicubic
 fps: 30/1
 format: NV12
 YUV mode: Rec. 709/Partial
info: NV12 texture support not available
info: P010 texture support not available
info: Audio monitoring device:
 name: Default
 id: default
info: ---------------------------------
warning: Failed to load 'en-US' text for module: 'decklink-captions.so'
warning: Failed to load 'en-US' text for module: 'decklink-output-ui.so'
libDeckLinkAPI.so: cannot open shared object file: No such file or directory
warning: A DeckLink iterator could not be created. The DeckLink drivers may not be installed
warning: Failed to initialize module 'decklink.so'
info: [pipewire] No captures available
info: FFMPEG VAAPI supported
info: [obs-websocket] [obs_module_load] you can haz websockets (Version: 5.0.1 | RPC Version: 1)
info: [obs-websocket] [obs_module_load] Qt version (compile-time): 5.15.6 | Qt version (run-time): 5.15.6
info: [obs-websocket] [obs_module_load] Linked ASIO Version: 102201
info: [obs-websocket] [Config::Load] (FirstLoad) Generating new server password.
info: [obs-websocket] [obs_module_load] Module loaded.
info: [vlc-video]: VLC 3.0.17.4 Vetinari found, VLC video source enabled
info: ---------------------------------
info: Loaded Modules:
info: vlc-video.so
info: text-freetype2.so
info: rtmp-services.so
info: obs-x264.so
info: obs-websocket.so
info: obs-transitions.so
info: obs-outputs.so
info: obs-filters.so
info: obs-ffmpeg.so
info: linux-v4l2.so
info: linux-pulseaudio.so
info: linux-pipewire.so
info: linux-jack.so
info: linux-capture.so
info: linux-alsa.so
info: image-source.so
info: frontend-tools.so
info: decklink-output-ui.so
info: decklink-captions.so
info: ---------------------------------
QLayout: Attempting to add QLayout "" to OBSBasic "OBSBasic", which already has a layout
QWidget::setTabOrder: 'first' and 'second' must be in the same window
info: ==== Startup complete ===============================================
info: No scene file found, creating default scene
info: All scene data cleared
info: ------------------------------------------------
info: pulse-input: Server name: 'pulseaudio 16.1'
info: pulse-input: Audio format: s16le, 44100 Hz, 2 channels
info: pulse-input: Started recording from 'alsa_output.pci-0000_00_1f.3.analog-stereo.monitor'
info: pulse-input: Server name: 'pulseaudio 16.1'
info: pulse-input: Audio format: s16le, 44100 Hz, 2 channels
info: pulse-input: Started recording from 'alsa_input.pci-0000_00_1f.3.analog-stereo'
info: Switched to scene 'Scene'
warning: Failed to glob scene collections
warning: [rtmp-services plugin] Successfully updated file 'services.json' (version 216)
warning: [rtmp-services plugin] Successfully updated package (version 216)
Attempted path: share/obs/obs-studio/images/overflow.png
Attempted path: /usr/share/obs/obs-studio/images/overflow.png
info: xshm-input: Geometry 1920x1080 @ 0,0
info: User added source 'Screen Capture (XSHM)' (xshm_input) to scene 'Scene'
info: ==== Shutting down ==================================================
info: Switched to scene 'Scene'
info: Switched to scene 'Scene'
info: pulse-input: Stopped recording from 'alsa_output.pci-0000_00_1f.3.analog-stereo.monitor'
info: pulse-input: Got 4904 packets with 1086068 frames
info: pulse-input: Stopped recording from 'alsa_input.pci-0000_00_1f.3.analog-stereo'
info: pulse-input: Got 2706 packets with 1173192 frames
info: All scene data cleared
info: ------------------------------------------------
info: [obs-websocket] [obs_module_unload] Shutting down...
info: [obs-websocket] [obs_module_unload] Finished shutting down.
info: [Scripting] Total detached callbacks: 0
info: Freeing OBS context data
warning: 1 views remain at shutdown
info: == Profiler Results =============================
info: run_program_init: 454.927 ms
info: ┣OBSApp::AppInit: 12.93 ms
info: ┃ ┗OBSApp::InitLocale: 0.755 ms
info: ┗OBSApp::OBSInit: 370.055 ms
info: ┣obs_startup: 0.705 ms
info: ┗OBSBasic::OBSInit: 297.563 ms
info: ┣OBSBasic::InitBasicConfig: 0.42 ms
info: ┣OBSBasic::ResetAudio: 0.117 ms
info: ┣OBSBasic::ResetVideo: 45.307 ms
info: ┣OBSBasic::InitOBSCallbacks: 0.005 ms
info: ┣OBSBasic::InitHotkeys: 0.039 ms
info: ┣obs_load_all_modules2: 53.407 ms
info: ┃ ┣obs_init_module(decklink-captions.so): 0 ms
info: ┃ ┣obs_init_module(decklink-output-ui.so): 0 ms
info: ┃ ┣obs_init_module(decklink.so): 0.067 ms
info: ┃ ┣obs_init_module(frontend-tools.so): 13.089 ms
info: ┃ ┣obs_init_module(image-source.so): 0.004 ms
info: ┃ ┣obs_init_module(linux-alsa.so): 0.001 ms
info: ┃ ┣obs_init_module(linux-capture.so): 0.337 ms
info: ┃ ┣obs_init_module(linux-jack.so): 0.001 ms
info: ┃ ┣obs_init_module(linux-pipewire.so): 1.451 ms
info: ┃ ┣obs_init_module(linux-pulseaudio.so): 0.001 ms
info: ┃ ┣obs_init_module(linux-v4l2.so): 2.083 ms
info: ┃ ┣obs_init_module(obs-ffmpeg.so): 0.418 ms
info: ┃ ┃ ┗nvenc_check: 0.315 ms
info: ┃ ┣obs_init_module(obs-filters.so): 0.011 ms
info: ┃ ┣obs_init_module(obs-outputs.so): 0.001 ms
info: ┃ ┣obs_init_module(obs-transitions.so): 0.003 ms
info: ┃ ┣obs_init_module(obs-websocket.so): 5.186 ms
info: ┃ ┣obs_init_module(obs-x264.so): 0.002 ms
info: ┃ ┣obs_init_module(rtmp-services.so): 0.106 ms
info: ┃ ┣obs_init_module(text-freetype2.so): 0.02 ms
info: ┃ ┗obs_init_module(vlc-video.so): 0.545 ms
info: ┣OBSBasic::ResetOutputs: 0.107 ms
info: ┣OBSBasic::CreateHotkeys: 0.024 ms
info: ┣OBSBasic::InitService: 0.873 ms
info: ┣OBSBasic::InitPrimitives: 0.09 ms
info: ┗OBSBasic::Load: 158.332 ms
info: obs_hotkey_thread(25 ms): min=0.052 ms, median=0.447 ms, max=10.071 ms, 99th percentile=7.389 ms, 100% below 25 ms
info: audio_thread(Audio): min=0.008 ms, median=0.068 ms, max=2.344 ms, 99th percentile=0.245 ms
info: obs_graphics_thread(33.3333 ms): min=0.047 ms, median=6.316 ms, max=26.791 ms, 99th percentile=12.809 ms, 100% below 33.333 ms
info: ┣tick_sources: min=0 ms, median=5.987 ms, max=24.285 ms, 99th percentile=12.422 ms
info: ┣output_frame: min=0.019 ms, median=0.224 ms, max=1.116 ms, 99th percentile=0.457 ms
info: ┃ ┗gs_context(video->graphics): min=0.019 ms, median=0.223 ms, max=1.115 ms, 99th percentile=0.456 ms
info: ┃ ┣render_video: min=0.014 ms, median=0.122 ms, max=1.008 ms, 99th percentile=0.312 ms
info: ┃ ┃ ┗render_main_texture: min=0.011 ms, median=0.117 ms, max=1.003 ms, 99th percentile=0.306 ms
info: ┃ ┗gs_flush: min=0.003 ms, median=0.083 ms, max=0.455 ms, 99th percentile=0.24 ms
info: ┗render_displays: min=0.001 ms, median=0.006 ms, max=2.973 ms, 99th percentile=2.429 ms
info: =================================================
info: == Profiler Time Between Calls ==================
info: obs_hotkey_thread(25 ms): min=25.135 ms, median=25.596 ms, max=35.162 ms, 42.0849% within ±2% of 25 ms (0% lower, 57.9151% higher)
info: obs_graphics_thread(33.3333 ms): min=32.24 ms, median=33.333 ms, max=34.268 ms, 99.2565% within ±2% of 33.333 ms (0.495663% lower, 0.247831% higher)
info: =================================================
info: Number of memory leaks: 0

ProblemType: Bug
DistroRelease: Ubuntu 22.10
Package: obs-studio 28.0.1+dfsg1-3
ProcVersionSignature: Ubuntu 5.19.0-29.30-generic 5.19.17
Uname: Linux 5.19.0-29-generic x86_64
ApportVersion: 2.23.1-0ubuntu3
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: Unity:Unity7:ubuntu
Date: Sun Jan 15 19:09:12 2023
InstallationDate: Installed on 2023-01-06 (9 days ago)
InstallationMedia: Ubuntu-Unity 22.10 "Kinetic Kudu" - Release amd64 (20221018)
SourcePackage: obs-studio
UpgradeStatus: No upgrade log present (probably fresh install)