I've been getting an endless security check loop on FF.V102.9 which just updated yesterday.I've had to activate my User Agent Switcher extension to get the site to load in the browser having the isssues and that's when I found out it was started with that FF update.

I'm running Firefox Developer Edition 112.0b2 and it works fine with MTS. Is the Security Check coming from Cloudflare? Can you screenshot it?

I had to turn UAS off to get the shot and load Paint to save it.I use hundreds of extensions on my borwsers and UAS is a user agent switcher that allows Firefox to mimic other versions and even other browsers on other systems.It's how I was able to get different results on enabling UAS while the site wouldn't load with UAS disabled.

@TadOlson I'm having no problems on my Firefox 111.0- are you using Firefox ESR?

I've got a portable ESR version as I still use Windows 7 and had gone though many bad updates in the past including fake updates when updating it automatically though a background service and getting dozens of "programs" that turned out to be just malware that installed themselves with no way to cancel out or abort them.I'm able to load though my UAS extension though not sure if it would load without enabling that first and it's also an issue on YouTube with their site loading up slightly broken.

Are you able to boot Firefox in troubleshoot mode and test the Modthesims site then?

To be clear this is NOT an MTS issue. It's actually a precaution that Cloudflare have in place as part of their Web Application Firewall. It's flagging your browser as a security issue. It's entirely possible that one of the "hundreds" of extensions is altering the UA in such a way as to trigger the safeguards. Either way, there is nothing I can do about it from my side. It's an issue specifically to your browser and your setup.

I've been trying to find the issue and it looks like it's just simply an issue with the latest update so others with the same version need to know how to fix it and I've had to use an extension just to get into the site and I've had a few extensioons disabled tecently and will check on them.
I've been testing with other later versions of Firefox using the user agent switcher extension and it's clearly a case of broke compatibility between one version of Firefox and the site's server.I've been able to loas the site pretending to be on at least a few different versions of FF than my current one.

The latest Release version is 111.0 though. The version 102.9 is only the latest within Firefox Extended Support, but that's for Enterprise customers really. Most regular desktop users should just use the Standard Release. Running a browser 26 versions behind is usually not a great idea.

Not a great idea to use an unsupported OS for web browsing either...

It might be the only option if a new computer is unavailable or no money is available to buy one even if the choices are available.I'll be updating my OS in the next day.

What other extensions are you running
MTS works just fine on FF
I am a dual-browers user (opera works fine there to btw)
It has to be another extension

I'm not sure what's happened and wanted to know if anybody else is having the same issue with the site loading.I've started installing the latest Windows updates as I'm stuck on Windows 7 until I'm able to invest in a new computer able to meet my needs.I've been trying to test to find of what is causing the issue and it really started just a few days ago that this site stopped loading correctly and is also affecting YouTube with them also loading wrong.

@TadOlson It's the same process you'd use for solving problems with your Sims 2 game. Load Firefox with all your addons disabled, see if you have a problem. If so then you know it's to do with that version of Firefox, if not then you know it's to do with an addon. You can figure out which addon it is by enabling 50% of them at a time and eliminating the ones that don't cause problems. But it's not a site issue as Tashiketh said.

I've got ti make a copy of it for that and start disabling them one at a time when I have the time to fid out if it is an extension or a glitch between the browser and a few sites and nothing to do with any extenstions.It might just be that my updating glitched out and it might clear up with the next browser update.

Hey what? Why? In Firefox ESR can't you just disable individual addons without uninstalling them? Go to about:addons and take a look. In later versions you can start in troubleshooting mode to disable everything, not sure if your version has that.

I've got a portable version and duplicating it is the easliest way to test without messing up my main functional copy just in case I made a mistake and disabled the wrong extension leaving the browser almost useless.I've tested with disablbling a few security ones that ight've been blocking things and it was still acting up which means it could just be a fauly update which happended to just a few users.