Here's the log file:
21:59:35.131: CPU Name: Intel(R) Xeon(R) CPU W5590 @ 3.33GHz
21:59:35.131: CPU Speed: 3324MHz
21:59:35.131: Physical Cores: 4, Logical Cores: 8
21:59:35.131: Physical Memory: 16384MB Total
21:59:35.131: OS Name: Mac OS X (NSMACHOperatingSystem)
21:59:35.131: OS Version: Version 10.11.6 (Build 15G18013)
21:59:35.131: Kernel Version: 15.6.0
21:59:35.142: hotkeys-cocoa: Using layout 'com.apple.keylayout.US'
21:59:35.142: Portable mode: false
21:59:35.463: OBS 22.0.3 (mac)
21:59:35.463: ---------------------------------
21:59:35.464: ---------------------------------
21:59:35.464: audio settings reset:
21:59:35.464: samples per sec: 44100
21:59:35.464: speakers: 2
21:59:35.465: ---------------------------------
21:59:35.465: Initializing OpenGL...
21:59:35.757: Loading up OpenGL on adapter NVIDIA Corporation NVIDIA GeForce GT 120 OpenGL Engine
21:59:35.757: OpenGL loaded successfully, version 3.3 NVIDIA-10.0.52 310.90.10.05b46, shading language 3.30
21:59:35.843: ---------------------------------
21:59:35.843: video settings reset:
21:59:35.843: base resolution: 1920x1080
21:59:35.843: output resolution: 1920x1080
21:59:35.843: downscale filter: Bicubic
21:59:35.843: fps: 30/1
21:59:35.843: format: NV12
21:59:35.843: YUV mode: 601/Partial
21:59:36.053: Audio monitoring device:
21:59:36.053: name: Default
21:59:36.053: id: default
21:59:36.053: ---------------------------------
21:59:36.102: os_dlopen(libpython3.6m.dylib->libpython3.6m.dylib): dlopen(libpython3.6m.dylib, 1): image not found
21:59:36.102:
21:59:36.102: [Python] Could not load library: libpython3.6m.dylib
21:59:36.261: No blackmagic support
21:59:36.306: [VideoToolbox encoder]: Adding VideoToolbox H264 encoders
21:59:36.458: [obs-browser]: Version 2.1.6
21:59:36.633: VLC found, VLC video source enabled
21:59:36.650: Ignoring old obs-browser.so version
21:59:36.650: ---------------------------------
21:59:36.650: Loaded Modules:
21:59:36.650: vlc-video.so
21:59:36.650: text-freetype2.so
21:59:36.650: rtmp-services.so
21:59:36.650: obs-x264.so
21:59:36.650: obs-vst.so
21:59:36.650: obs-transitions.so
21:59:36.650: obs-outputs.so
21:59:36.650: obs-filters.so
21:59:36.650: obs-ffmpeg.so
21:59:36.650: obs-browser.so
21:59:36.650: mac-vth264.so
21:59:36.650: mac-syphon.so
21:59:36.650: mac-decklink.so
21:59:36.650: mac-capture.so
21:59:36.650: mac-avcapture.so
21:59:36.650: linux-jack.so
21:59:36.650: image-source.so
21:59:36.650: frontend-tools.so
21:59:36.650: coreaudio-encoder.so
21:59:36.650: ---------------------------------
21:59:36.650: ==== Startup complete ===============================================
21:59:36.703: obs-data.c: [obs_data_create_from_json] Failed reading json string (-1): wrong arguments
21:59:36.947: All scene data cleared
21:59:36.947: ------------------------------------------------
21:59:37.288: coreaudio: device 'AudioBox USB' initialized
21:59:37.439: Switched to scene 'Scene'
21:59:37.439: ------------------------------------------------
21:59:37.439: Loaded scenes:
21:59:37.439: - scene 'Scene':
21:59:37.439: - source: 'Window Capture 2' (window_capture)
21:59:37.439: - source: 'Text (FreeType 2)' (text_ft2_source)
21:59:37.439: - source: 'Display Capture' (display_capture)
21:59:37.439: - scene 'Scene 2':
21:59:37.439: - source: 'Display Capture 2' (display_capture)
21:59:37.439: - source: 'Window Capture' (window_capture)
21:59:37.439: ------------------------------------------------
21:59:37.740: adding 23 milliseconds of audio buffering, total audio buffering is now 23 milliseconds
21:59:37.933: adding 23 milliseconds of audio buffering, total audio buffering is now 46 milliseconds
21:59:41.881: ---------------------------------
21:59:41.881: [x264 encoder: 'simple_h264_recording'] preset: veryfast
21:59:41.881: [x264 encoder: 'simple_h264_recording'] profile: high
21:59:41.881: [x264 encoder: 'simple_h264_recording'] settings:
21:59:41.881: rate_control: CRF
21:59:41.881: bitrate: 0
21:59:41.881: buffer size: 0
21:59:41.881: crf: 23
21:59:41.881: fps_num: 30
21:59:41.881: fps_den: 1
21:59:41.881: width: 1920
21:59:41.881: height: 1080
21:59:41.881: keyint: 250
21:59:41.881:
21:59:41.891: [CoreAudio AAC: 'simple_aac_recording']: settings:
21:59:41.891: mode: AAC
21:59:41.891: bitrate: 128
21:59:41.891: sample rate: 44100
21:59:41.891: cbr: on
21:59:41.891: output buffer: 1536
21:59:41.895: ==== Recording Start ===============================================
21:59:41.895: [ffmpeg muxer: 'simple_file_output'] Writing file '/Users/luke/Movies/2018-09-13 21-59-41.mp4'...
22:00:21.838: [ffmpeg muxer: 'simple_file_output'] Output of file '/Users/luke/Movies/2018-09-13 21-59-41.mp4' stopped
22:00:21.867: Output 'simple_file_output': stopping
22:00:21.867: Output 'simple_file_output': Total frames output: 1140
22:00:21.867: Output 'simple_file_output': Total drawn frames: 357 (1199 attempted)
22:00:21.867: Output 'simple_file_output': Number of lagged frames due to rendering lag/stalls: 842 (70.2%)
22:00:21.885: ==== Recording Stop ================================================
22:01:13.168: Failed to read log file /Users/luke/Library/Application Support/obs-studio/logs/