A few things, showing the version number of simple machines, and showing it as out of date, is an open invitation to anyone who follows vulnerabilities to exploit them.
At the very least, pull that from the footer template chunk so that automated bots can't detect it.
I access linuxquestions.org almost daily, and have never seen anything problematic about it. Cloudflare issues might reflect locale of access, I in general almost never see cloudflare challenges.
Those are I believe javascript based, so you do have to allow javascript for LQ.
I am posting again because I again had server 500 failures, along with full post rejection without any alert, obviously caused by a misconfigured security rule, probably on the web server.
I posted this in another bug thread here, but the issues are not minor, but at least get rid of the open advertisement that the forum software is seriously out of date, just as a minimum. This takes about 2 minutes to get rid of since it will just be something in a template somewhere.
A few other things, https should not be optional, otherwise there is almost no point in using https, that might of course require ca-certificates be added to the tinycore base install, which pulls in openssl, so I can see the reluctance there.
You can make apache/web server rules that force use if the browser supports it, if I remember right, and falls back to http if the browser does not support it. Not positive, I know you can do it in code, but I think you can do it in configurations too, like .htaccess.
As someone above suggested, first of all, update simple machines to current, and if you can't update it due to some linking between the broken wiki software package and simple machines, that is why you don't do that, break that connection since the wiki doesn't work anyway.
Note that the open display of all the error data in the wiki link is STILL present, which means nobody is taking care of this stuff.
I repeat my suggestion: do yourself and your users, and your potential new users, a favor, and move the forums to lq and call it good and fixed. Then maybe install the wiki software package after removing the mods, if any, to attempt to connect the two user databases, and go on, hopefully you didn't lose all the data in the wiki, but if you did, ouch.
Running this stuff over time is a real pain, and a real commitment, but the ongoing presence of nothing but red flags indicates to me that in a sense, the facts have already made the decision, and it's just a matter of catching up to the facts.
In the old days I would have volunteered to help resolve this, as long as I was allowed to actually fix it, and not add more hacks and patches, but since I don't know either software package, experience guides me to not do that, or to even try.
But if I were to try, I'd figure out if there were any mods applied to link the databases, undo those mods, then do reinstalls of both forum and wiki software, current latest version, and pray it worked. If it did not work, I'd move the forums to lq.org and set up a new wiki package, and never try to repeat the errors that led to the failures.
I find, speaking for myself, the work required to maintain over many years this stuff requires always keeping up with fixes, updating, patching, etc, and it can't be done if you are not an active experienced web developer, except maybe for wordpress, which tends to upgrade fairly cleanly, but it's also annoying to run over time, and has a terrible forum feature, more of a hack than anything else, so not recommending that.
Again, re cloudflare, you want to leverage that existing protection, dealing with cloudflare is another pain for admins, but if it's all set up and working, you don't need to deal with it, beyond maybe a few users enabling javascript, or not being able to access site without a gui browser that runs javascript.
Actually, I take that back, I just tested our cloudflare protected site, and it loaded fine with lynx, so that's not an issue. That's lynx hitting a forced https page, by the way, through cloudflare, and lynx is about as basic as cli browsers get.
The hacker in me itches to try to fix your codebase, but the experienced developer in me knows that would lead to nothing but pain, but in many cases, just stripping out any mods, totally removing them, then updating the software in question to current version, may work.
Given your wiki simply doesn't work at all, and is displaying private system errors to the world, I would suggest this is the perfecct time to dump what you were trying to do, and update the software, remove the hacks, and then see what you have running and what doesn't work.