Try the following:
- Please ensure the pay group has been enabled (Payable Administrator > Setup > Lookup > Purchasing > Pay Group)
- Go to supplier > Entry
- Search for the desired Supplier
- Go to Invoice Management > Payments Tab > Add the Supplier site with the corresponding pay group.
- Save and retry.
Please obtain a FND Debug log on the issue and upload the log to a free hosting site and provide the link here for our reference.
Meanwhile also raise an SR.
How to enable and retrieve FND debug log messages (Doc ID 433199.1)