Firefox download appears to be corrupt

[omentic]

Prerequisites

• ✔️ I verified that this is not a filter issue
  • Filter issues MUST be reported at filter issue tracker
• ✔️ This is not a support issue or a question
  • Support issues and questions are handled at /r/uBlockOrigin
• ✔️ I performed a cursory search of the issue tracker to avoid opening a duplicate issue
  • Your issue may already be reported.
• I tried to reproduce the issue when...
  • [ N/A ] uBlock Origin is the only extension
  • [ N/A ] uBlock Origin with default lists/settings
  • ✔️ using a new, unmodified browser profile
• [ N/A ] I am running the latest version of uBlock Origin
• ✔️ I checked the documentation to understand that the issue I report is not a normal behavior

Description

When attempting to download the uBlock Origin extension from the Firefox AddOns, it intermittently gives a Download failed. Please check your connection. error or The addon downloaded from this site could not be installed because it appears to be corrupt.

A specific URL where the issue occurs

Here's the addon page.

Steps to Reproduce

1. Try to download the uBlock Origin extension from the addon page.
2. The download fails.
3. Troubleshoot for a bit, check GitHub, and cry a little.

Expected behavior:

Addon downloads successfully.

Actual behavior:

Addon does not download successfully.

Your environment

• uBlock Origin version: None installed
• Browser Name and version: Firefox [66.0.1] (Stable!! different than Add-on would not install on Firefox Linux beta: "appears to be corrupt" #124)
• Operating System and version: Manjaro Linux, 18.0.4 Illyria

I've restarted my browser a couple of times, and deleted extensions.json. Other extensions appear to download correctly.

[uBlock-user]

Disable all other extensions and try again.

Also try -- https://support.mozilla.org/en-US/kb/refresh-firefox-reset-add-ons-and-settings

This sometimes happens on AMO. Just try again later.

The addon downloaded from this site could not be installed because it appears to be corrupt

Clear browser cache.

[kulfoon]

Not uBO's issue, it's a browser or connection or server's issue: gorhill/uBlock#1413 + #124

[uBlock-user]

Duplicate of gorhill/uBlock#1413