If this is a "permission" associated with a particular site, while you are viewing that site, tap the padlock or globe icon to call up a floating panel which should let you change site permissions. I'm attaching a sequence of screenshots from Firefox 50 as an example.

Thank you for responding. I did just try that but it shows it is a Secure Connection and not an Insecure Connection. Anything I can do now?

Sorry, that was the only place I can think of to find site-specific permissions. Maybe it was a different prompt for some other kind of block. Do you have any add-ons (menu > Tools > Add-ons)?

Again, thanks for responding. I'm thinking we might have to reinstall Firefox. What do you think?

You could try:

menu > Settings > Clear private data

Clear the checkboxes you do not want, but select Site Settings to remove site-specific settings, then click Clear Data.

Any difference?

You also could reinstall.

Is there any data you cannot live without (e.g., bookmarks)? Assuming not, you could go to

Android Settings > Applications > Application Manager > Firefox > Storage > Clear Data

I think that will reset everything in Firefox.

You have been very helpful. Hopefully one of these suggestions works. It is late now, but I will try that tomorrow after work.

Thanks.

The Site Settings on the Clear Private Data unfortunately did now work. I will probably reinstall Firefox.

Again, thank you so much for your time.