Generally you'll want to post the crash log but try the following first:
1. The new Windows 10 Hardware-accelerated GPU scheduling ("HAGS") added with version 2004 is currently known to cause performance and capture issues with OBS, games and overlay tools. It's a new and experimental feature and we recommend disabling it via
this screen or
these instructions.
2. Two instances of OBS are running. If you are not intentionally running two instances, they will likely interfere with each other and consume excessive resources. Stop one of them. Check Task Manager for stray OBS processes if you can't find the other one.
3. Run OBS as Admin. Right click on shortcut, properties, advanced, check box, ok, apply, ok.
If you'll able to keep OBS open at that point then:
4. Display and Game Capture Sources interfere with each other. Never put them in the same scene (Stream).
5. Your audio device has a sample rate that doesn't match OBS. This can result in audio drift over time or sound distortion. 48000 Hz is recommended.
OBS Sample Rate:
44100 Hz
Speaker/Headphone (Realtek High Definition Audio):
48000 Hz
To fix this go to OBS Settings, Audio, General and set the Sample Rate to 48 kHz.