Greaselion content script sometimes doesn't load until restarting browser

[emerick]

Create a Greaselion.json file like the following and a simple script that just prints Hello, world! to the console:

  {
    "urls": [
      "https://twitter.com/*",
      "https://*.twitter.com/*"
    ],
    "scripts": [
      "myscript.js"
    ]
  }

If you launch the browser clean (with no open pages) and then navigate to https://twitter.com/emerick, once in a while the content script will not load at all. This occurs maybe 1 in 10 or 1 in 20 times. In addition, no amount of refreshing the page or creating new tabs will cause the content script to load; the only recourse I've found is to restart the browser. I don't see any relevant error messages in the log or console when this occurs, unfortunately.

[emerick]

Actually, I can make this happen every time by adding some additional entries to Greaselion.json. I added 10 just now and it occurs every time.

[LaurenWags]

Per internal discussions, this issue should be tested when Twitter tipping with Greaselion lands (projected to be 1.17.x). As such, I have logged a follow up issue (#11998) for that milestone and will be marking this one as QA/No. Please adjust if needed.