You can check the Web Console for WebGL related messages.

• "3-bar" menu button or Tools -> Web Developer
• https://developer.mozilla.org/en-US/docs/Tools/Web_Console

You can check the Graphics section on the "Help -> Troubleshooting Information" (about:support) page to see if there are issues reported about WebGL.

• https://support.mozilla.org/en-US/kb/use-troubleshooting-information-page-fix-firefox

OK, I missed your troubleshooting information.

webgl1Renderer: WebGL is currently disabled.
webgl1Version: -
webgl1DriverExtensions: -
webgl1Extensions: -
webgl1WSIInfo: -
webgl2Renderer: WebGL is currently disabled.
webgl2Version: -
webgl2DriverExtensions: -
webgl2Extensions: -
webgl2WSIInfo: -

You can check webgl.disabled on the about:config page and make sure it is set to false.

• webgl.disabled = false

You can also possibly force WebGL by setting this pref to true.

• webgl.force-enabled = true

You can open the about:config page via the location/address bar. You can click the button to "Accept the Risk and Continue".

• https://support.mozilla.org/en-US/kb/about-config-editor-firefox

Cor-el, Thank you very much. I know how to enable and disable at will, now I can get the info I need then disable WebGL again. Very useful!!! Timmy