I'm occasionally getting a "Sorry You're Banned" Message

[Serpius]

looks like the problem is due to IP bans done on your forum.
your IP addresses should be checked with the banned IP list.

forum admin panel >> Configuration >> Banning

Hmm... I forgot all about that part. Didn't think of the IP banning part. 

That could be it.

[Simon Harris]

Thanks, guys!

I'm discovering new things about MYBB.

If I go into Banning and delete the ban on the IP I'm using everything works fine for the rest of the day.

However, I'm using a VPN and the next day I log in OK and then after about 10 mins I get "You're banned" again.

Is it possible that new bans are being created by a bug or a hacker?

[frostschutz]

This user has been denied support.

maybe you're banning people who use the same vpn service xD

or you have an addon that bans spammers who spammed elsewhere, thus introducing new bans on your own site

[Serpius]

Thanks, guys!

I'm discovering new things about MYBB.

If I go into Banning and delete the ban on the IP I'm using everything works fine for the rest of the day.

However, I'm using a VPN and the next day I log in OK and then after about 10 mins I get "You're banned" again.

Is it possible that new bans are being created by a bug or a hacker?

Well, normally, most people don't use a VPN. VPNs will create dynamic IPs that sometimes fall into the banned list of IP addresses. 

I think that is what is happening to you.

I think if you stop using the VPN, everything will go back to normal. 

Why are you using a VPN to login your own website? That's perplexing to me.

[Simon Harris]

I have the VPN activated all the time.

I'm permanently logged on to my site. Occasionally, when I'm working on something, I get the "You're banned" message!