While attempting to upgrade your account to ManageFlitter Pro, there is a chance payment may fail to be processed.
This typically happens because there is insufficient money in your PayPal balance, or your funding sources (such as credit cards) are not up to date.
We recommend making sure that your funding sources are up-to-date and attempting to upgrade again.
Occasionally PayPal will block payments from some accounts completely. You can read more about blocked payments here.
Some customers have had success creating new PayPal accounts and using those for transactions. If all other methods fail, we recommend this approach.