How do I get a specific error for corrupt Firefox extensions?

Question

Background:

I'm working on an extension for Firefox and obviously made a mistake somewhere. This is my first extension, so I wouldn't be surprised if the problem ends up being something simple.

The issue is though that I can't even get a decent error from Firefox to hunt down the problem.

The Problem

When I attempt to install my extension by dragging the XPI file into the Awesome/Location bar, I get an error message stating "This addon could not be installed because it appears to be corrupt." This is not a terribly useful error for someone trying to develop and extension.

Does anyone know of a way to get a more verbose error message? Googling around I wasn't able to find anything myself.

Answer 1

Firefox has an error console under "Tools">"Web Developer">"Error Console" (ctrl+shift+j for me).

Open up the error console, there will probably be a lot of warnings already listed. Clear all of these and then try to do something, i.e. install your extension. The console will update automatically.

Answer 2

I ran into similar issue on Windows 10. Same extension works great in Opera/Edge/Chrome without any errors. I tried different solutions that I found on the internet and in the end nothing helped me, so I just downloaded my own extension from Opera as a zip file. Works like a charm!

Go to https://addons.opera.com/developer/package/_your_package_here/ Click on Versions tab Pick the version you want to download and there you have a download button under Info Package