I'm having trouble with my RSForm with ROpayment. When I try to submit it I get this error: 0 - Unsupported operand types: int * string
When there is no payment option in the form all works well.
This is the form: https://popkoorrepeat.nl/kaarten-repeat-s-kerstproeverij-bestellen
Joomla version: 3.10.12
Latest RO Payment
Latest RS Form PRo
PHP 8.0
Hope someone can help.
With kind regards,
Rachel Walraven