I didn't find a problem.

I reactivated them one at time, joined after every one and everything worked fine.

I then poosted here to say the problem seemed to have dissapeard and the problem returned after that.

well, it is definitely caused by the 3rd party plugin, because if you leave only default plugins, there's no such error

I will try that againg this afternoon, I just off to work now.

I will let you know as soon as find something.

Cheers.

alright, keep us updated

As of this moment these are the only plugins I have activated on my site.

Speed optimiser
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about 2 in 20 attempts to sign up have been sucsessful and the problem remains. I really don't think this is plugin issue.

This was a new install using sofculous softaculous and it did not install the forums the forums plugin correctly as you had to help me fix it. i am just wondering if something else has not been installed correctly.

Probably there was some server fail while installing via softaculous, but I'm not sure about that. 

I was testing the installation via softaculous recently and everything went good, so I can't confirm this. 

I see that you have changed your admin access details, can you PM new one I'll check the issue again. 

Shaun, I can't reproduce the issue, I registered 7 times with no issue. 

Try to clear the browser cache

Thanks for your time Ross. i promise to donate to oxwall in appreciation of your help.

I am actually more gutted you cant find the problem though as I just don't know what to do next.

I will start the process of adding the plugins back one at time.

Thanks again.

I found the problem,

It seems to be caused by OxArt Speed Optimiser.

The problem does not start imediatly after activating the plugin but is usually noticable a few minutes later hence the reason why I could re install all the plugins and the site would work fine until i returned a few hours later.

I am now off to cantct the developer.

Thanks everyone.

Great, thanks for letting us know.