Lots of people are using 8.2 series
The error your reporting seems to indicate the captcha field does not exist on your usergroups table which is added in 8.0 to 8.1
I would suggest you do your upgrade and then if you have an issue look with phpmyadmin if the field exists on that table.
If you continue to have the issue then I would need to see the site in question.
You can edit pp-inc.php and this code.
Code:
Content visible to verified customers only.
change that to this
Code:
Content visible to verified customers only.
That should show the specific full error where I can comment more here.