Please read and follow directions and recommendation on the analizer:
OBS (Open Broadcaster Software) is free and open source software for video recording and live streaming. Stream to Twitch, YouTube and many other providers or record your own videos with high quality H264 / AAC encoding.
obsproject.com
Also, remove any plugin you have installed and test it without it. Normally crashes or other issues on closing OBS are due to a plugin.
Don't use advance output, keep it on simple output. The best way to fix any error you have in it is running the Auto-configuration Wizard and applying the settings it gives. Then restart OBS (!important) and test as is.
The issue with the network adapter could be due to the outdated windows or outdated network driver. In the network driver settings you can force the 1Gbps connection as long as the router and moden are capable of this.