User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:55.0) Gecko/20100101 Firefox/55.0 Build ID: 20170629005143 Steps to reproduce: 1. View an extension's resources using moz-extension://{id}/ 2. Click on any links (to a folder or a file) Actual results: Nothing happened Expected results: The directory page of the folder should show, or the file should be opened.

Jim, any idea?

The link to the resource is not "moz-extension://" but "jar:file://", maybe related to bug 1334550?

Thanks for reporting this. I'll try to narrow down what introduced this with mozregression. I tested on Mac and can reproduce this after setting "extensions.webextensions.protocol.remote" to false in about:config (changing this setting requires a browser restart). That setting should disable the work done in bug 1334550. Either way, clicking on a link from the moz-extension://<UUID> listing doesn't result in a request being sent to the ExtensionProtocolHandler.

This doesn't seem like a new problem. I reproduced this with build 55. I'm wondering if it's related to 1256122. Moving this over to the Toolkit -> WebExtensions component.