Can't submit credit card payment after update to 5.2.1/5.2.2 (Joomla)
As per my knowledge CiviCRM  for version >= 4.6 never allowed to do offline credit card payment either for event registration or membership purchase or record of contribution for Paypal Standard payment processor or any other processor that is Website based gateway i.e payment information like credit or debit card not collected from CiviCRM forms. It does allow for payment processor like Paypal Express or Pro. Even i believe for Paypal standard CiviCRM doesn't show credit card section on online form. Adding paypal pro payment processor might be helpful.

Thanks

Pradeep