After registration SQL Error

[Wazzyl]

Okay, I got informed by a user from Twitch in my chat that people cant actually register on my website, you can fill in all the information and when you click register you will see the following issue...

How can I fix this?
nobody can register on my website, it is so annoying...

and nope it has nothing to do with waiting, it's doing it all the time, and I am sick of all the hard work and nothing is working correctly.