I created a template in the issue section of the project https://github.com/tilepieces/tilepieces/issues. If you have time, feel free to fill it in with your bug! I've been told something like this before, I think the error lies in your firefox privacy settings, but I can't be sure. Then, you use linux, I don't think you will have problems starting the node.js version (https://www.npmjs.com/package/tilepieces). You can see if the error keeps showing up