I wrote my extension, packed as zip with Windows explorer (Send To - Compressed folder) and successfully uploaded it to AMO (successful auto verification). It still waiting for manual verification. Trying to install it from extension page and after accepting notification about unverified extension download process begin, but after it finish exeption message shown that says that addon can't be installed because of it's corrupted. Web Extension is pretty simple: 1 background script + 1 content script + 1 content css + few icons and manifest files Content script node in manifest contains "matches" property.