Overgrow reports an issue where the “CSS change notifier crashed” error occurs when updating a .scss file on a development server, requiring manual page reloads to see changes. The error indicates a No such file or directory issue for discourse-custom-plugin.scss, which is registered via register_asset in plugin.rb. Overgrow notes this is their only stylesheet and hasn’t occurred with other plugins using the same method. j.jaffeux requests a repository to help troubleshoot. Since Overgrow states it is a local custom testing plugin without a repo, j.jaffeux advises creating a minimal repository by copying the plugin and removing unnecessary code until the error is reproduced. Overgrow agrees to attempt replication in a fresh repo.
It can be a lot of things, even your path seems unexpected to me here, but honestly if you want us to dig this, build us a simple repository demonstrating the issue.
Make a copy of your plugin, and remove stuff till there’s the minimum needed for the error.