See if this helps; Type about:preferences#advanced<enter> in the address bar. Under Advanced, select General Turn off Warn me when websites try to redirect or reload the page.

Many thanks for your answer Fred McD, but I do not have the option 'Warn me when websites try to redirect or reload the page' in the general tab - I don't even an 'Advanced' tab at the top of the page anymore. Ref. Firefox v. 56.0.1. (64 bit) in Win 10.

You didn't follow the instructions correctly. Please try again.

There is also in the new version; Find In Options (upper right).

The Options page layout changed in Firefox 56 -- as you noticed! "Warn me when websites try to redirect or reload the page" is no longer included there.

Here's the alternate way to modify that setting:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button accepting the risk.

(2) In the search box above the list, type or paste access and pause while the list is filtered

(3a) TO TURN OFF: If the accessibility.blockautorefresh preference is bolded and "modified" or "user set" to true, double-click it to restore the default value of false

(3b) TO TURN ON: Double-click the accessibility.blockautorefresh preference to switch it from false to true

Success?

Fred McD - in that case you mustn't have give the instuctions correctly as I followed YOUR instructions TO THE LETTER. Many thanks.

jscher2000 - Many thanks, this has solved my problem!

FredMcD said

Type about:preferences#advanced<enter> in the address bar.

Not about:preferences (see your screen shot)

mckendrick said

Many thanks for your answer Fred McD, but I do not have the option 'Warn me when websites try to redirect or reload the page' in the general tab - I don't even an 'Advanced' tab at the top of the page anymore. Ref. Firefox v. 56.0.1. (64 bit) in Win 10.

I had the same problem that you did - I had added the always https Add-on - when I disabled it, the problem stopped. The browser worked for https sites, but made me redirect for non-secure sites.

My problem came back shortly after it seemed to be fixed - I was going to uninstall FF, clean the registry, then reinstall - but noticed that there was a new file installed by Firefox today, so uninstalled it, then went back to about:preferences#advanced and clicked on privacy and security. There is an option there (the default) that allows FF to install and run studies - I unchecked that and so far haven't had any problems