This issue can be replicated easily when handling vendor bill payment... If you add a tax of 2 different scopes with two corresponding different account types... For example in my case, I added a 15% Purchase Tax (paid to an Current Asset COA,  111200 - Tax Paid)  and I also added a -10% Withholding Tax (paid to a Payable Account I set up, tied to the COA, 220223 - WHT payable) ..... This configuration will generate an error, because the Withholding Tax account is a Payable Account instead of a Current Liability Account. This will happen anytime you mix a Payable Account with a receivable or Expense Transaction. If this was your case, Change the tax account type from Payable to Current Liabilities OR from Receivable to Current Assets... This will fix the issue immediately. You should now be able to Validate and Register Payments after this. 

If this answer wasn't helpful, please describe your current operation so I can be of further assistance. 

In my case the receivable account in journal entry was not as the same as in the invoice itself , an accountant has modified the journal entry manually without updating the receivable account related to the invoice

Hello! I'm having exactly the same problem. Did you find a solution? (I don't have enough karma to comment)

Tamara is on the right track with the answer. But I will just add that not only taxes are involved. In my case an item on the invoice was set to an account type "Payable". An another item was expenses.  There was no warning, until the error message to register payment came up. 

To correct it all items on the invoice was set to Expenses and the tax account was "Current liabilities".  Then it worked OK.

Hello! I'm having exactly the same problem. Did you find a solution?

My version is 10.

Check the counter account on your payment journal or your payment template.