Hi

This option is currently unavailable in Firefox for Android. It may be included in a future update.

Thank you, this saved me a lot of time of trying in vain!

I'll have to use Opera for this use case in the meantime then; hopefully it won't be long before it's supported in Firefox once more.

I use File Manger Plus (recommended). You can set it to open HTML/txt in Firefox as default app. This is the only way I've manged to make it work.

Hi This option is currently unavailable in Firefox for Android. It may be included in a future update.

Which future update? Because I still don't see it

This used to work in earlier versions of Firefox for Android. I have a web app (that I wrote, all javascript) that is installed on my phone. I didn't use it for a few months, and then when I went to use it, I got one brief flash of some kind of permission error, and then a blank page... and starting again from the saved bookmark just gives me a blank page without even the courtesy of an error message.

This is a serious regression, to not be able to access file: URLs.

Don't know if the option is supported already, but I've got the same problem in Firefox ver. 89.1.1 Got it to work by enabling "Remote debugging via USB" in Android's Firefox and connecting it to the Firefox in my PC. Then I inspected the only open tab. On the phone there was the URL of my local HTML file in the address bar, but on the PC it said "about:blank". I went ahead and typed the URL in my PC and hit Enter and then it finally loaded the HTML file on the phone. Sadly, it doesn't work after closing and re-opening the tab. Guess I will just try to never close that tab.

I use File Manger Plus (recommended). You can set it to open HTML/txt in Firefox as default app. This is the only way I've manged to make it work.

This worked for me. Thanks. Obviously they mean File Manager Plus...