As your site’s webmaster, that person is you. Regardless of how the error happened or developed. The best way forward is to enable Joomla’s public debug errors as was suggested to you before.
I know this might seem intimidating, but it’s a configuration file rather than actual code, and the default can be easily restored from a fresh copy of Joomla if anything goes wrong. Once you have that enabled, Joomla should be able to give you a more detailed error message. I would like to help you, but this is something where you’ll have to help us help you.
Yes I accept that, and thank you very much for your help.
That site I think the best thing to do would be for us to build it again rather than try to fix it, it will be quicker. It is impossible for me to even attempt to try and fix something I never broke. I do think that djextensions could be one of the problems on the site though. It is not compatible with Joomla 6 I couldn’t even get it to work on the new slte in the backend. The new site is currently saving fine, which does make me think that something has corrupted somewhere across the line, either code on the site or the sector. This one is on a fresh Joomla 6 extension on Softaculous rather than through FTP on an old version and then updated with possible errors through Admin, so we might get on a bit better.
Thanks to everybody for their help and time, I have never seen a site do that before, it displayed and loaded perfectly in the admin, but just never saved, cleared the cache, nothing. Hopefully we get on better with this new one lol. I will clear the old one off when I get a chance once I know for sure the new site is working.