When you say not working what do you mean, does it not show in the list of sources or does something no work when you configure the source?
The only thing I can see in the logs is that you may have tried to install the browser plugin from old OBS? If you have then that's your problem. Uninstall OBS studio, delete all the files from the install directory and then reinstall, browser source is part of the base install for OBS studio, no plugins are required