Does it help if you enable HTTPS-Only mode and create an HTTPS-Only exception for "http://docs.imsidesign.com" ?

• https://support.mozilla.org/en-US/kb/https-only-prefs

Check out; Support Forum discussions https://support.mozilla.org/en-US/forums/support-forum-contributors/715468 User: Firefox only allows access if https-Only Mode is turned off ENTIRELY

I tried adding "http://docs.imsidesign.com/projects/TurboCAD-2021/turbocad-2021-user-guide-publication/Customized-Programming/Parametric-Part-Script-Editing/" to the Manage Exemptions. It created "http://docs.imsidesign.com" in the list. I save the list. I then tried to go the address I entered but Cloudflare still intercepts the address, as it has "https..." in the address bar.

Do I need to uninstall Firefox?

Try to use "Forget About This Site" to remove prossible secure HTTPS remnants (https://) to this origin.

You can remove all data stored in Firefox for a specific domain via "Forget About This Site" in the right-click context menu of an history entry ("History -> Show All History" or "View -> Sidebar -> History").

Using "Forget About This Site" will remove all data stored in Firefox for this domain like history and cookies and passwords and exceptions and cache, so be cautious. If you have a password or other data for that domain that you do not want to lose then make sure to backup this data or make a note.

You can't recover from this 'forget' unless you have a backup of involved files.

If you revisit a 'forgotten' website then data for that website will be saved once again.

• https://support.mozilla.org/en-US/kb/delete-browsing-search-download-history-firefox

I tried "Forget About This Site". I made sure it was removed from all of my history and bookmarks. When I put in "http://docs.imsidesign.com/" it still goes to "https://docs.imsidesign.com/"

Are you using a private window to visit the site?

When I try the address in a private window, this appears in the Browser Console:

> HTTPS-First Mode: Upgrading insecure request “http://docs.imsidesign.com/” to use “https”.

This is something separate from the "HTTPS Only" feature, which you can manage in detail. Since Firefox 91, the "HTTPS First" feature is automatically enabled in private windows (Firefox 91 introduces HTTPS by Default in Private Browsing). That feature does NOT allow user exceptions.

You might need to disable "HTTPS First" and enable "HTTPS Only" in private windows to find the best balance of convenience and protection.

Disabling HTTPS First in private windows

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

More info on about:config: Configuration Editor for Firefox. The moderators would like us to remind you that changes made through this back door aren't fully supported and aren't guaranteed to continue working in the future.

(2) In the search box in the page, type or paste dom.security.https_first_pbm and pause while the list is filtered

(3) Double-click the preference to switch the value from true to false

You can close this tab now.

Enabling HTTPS Only in private windows

You can set this up on the Settings page. See: HTTPS-Only Mode in Firefox.

I filed a new bug report about that site. No need to add comments, and I wouldn't expect any quick changes because it's an odd situation.

https://bugzilla.mozilla.org/show_bug.cgi?id=1747673

If network.trr.mode = 2 then I also get redirected to HTTPS and the website fails to load (521 error). With network.trr.mode = 0 it works.

I'm NOT using a private window. I changed "dom.security.https_first_pbm" to false. That did not make any difference.

I'm NOT using a private window. I changed "dom.security.https_first_pbm" to false. That did not make any difference.

If network.trr.mode = 2 then I also get redirected to HTTPS and the website fails to load (521 error). With network.trr.mode = 0 it works.

Hmm, I could not replicate the problem in a regular window, only a private window with HTTPS First enabled in private windows. However, I was using local DNS.

If I enable DNS over HTTPS (cor-el mentioned the about:config method for that), then I also have the problem in a regular window.

That is difficult to understand, since the local DNS and Cloudflare DNS servers both seem to be returning the same address: [2606:4700:3033::ac43:8ba6]. Does enabling DNS over HTTPS also trigger some kind of "HTTPS First" behavior?

I'd like to try uninstalling Firefox then reinstalling it. How do I save my bookmarks? Does uninstall leave any files? (Many programs leave something)

Thanks

Historically, when you uninstalled, none of your data was removed. I think now the uninstaller might ask whether you want to remove your data or keep it. It also may offer the Refresh option. More on that: Refresh Firefox - reset add-ons and settings.

HOWEVER, why do you think uninstalling and reinstalling would give you different results? Did you already try turning off DNS over HTTPS? Firefox DNS-over-HTTPS.

I uninstalled and reinstalled Firefox. It still goes to HTTPS even though Don't enable HTTPS only mode is selected.

The DNS over HTTPS feature is a completely different setting: Firefox DNS-over-HTTPS.

THANK YOU!!!. for the link. That explained what I needed to know. I followed the instructions and now I can access the domain in Firefox.

Thanks Again, Rich Henderson

I was able to go back and "Enable HTTPS-Only Mode in all windows" then enter "http://docs.imsidesign.com/" in the "Manage Exceptions" window.

Thanks again Rich Henderson