Steven @ Juicebox wrote:

Hi.
Thank you for reporting this issue.

It looks like the change was introduced in Firefox 95.0 (but I can't find any relevant documentation).
It appears that the configuration option you now need to toggle in Firefox's about:config is security.fileuri.strict_origin_policy, from true to false.

I'll update the relevant 'Tips and Tricks' post here.

I hope this resolves your local viewing problem.
Please let me know how you get on.

That seems to have worked! Thank you!

Hey guys - With the latest Firefox update (I'm on a Mac, 10.15.7 (Catalina) + FF version 95.0.2) I have started getting the config file not found error again when attempting to open a local file. I had previously done the 'privacy.file_unique_origin' fix, and had been having no issues opening local galleries in Firefox until today. My 'privacy.file_unique_origin' setting is still set to false, and I haven't changed anything in the coding of my files so unsure why they no longer work. Any thoughts on what to try?

Thanks!