Hello,
Sorry to say but your mentioned concern and issue isn’t related to Theme end. You might be using some plugin related to Payment on your Site which might have some issues or errors generating. So, you need to contact the respective Plugin Support in this regard. They will guide you through.
Further, while searching we came across some Articles in this regard related to your PayUMoney concern, please check these. It might help:
https://givewp.com/documentation/add-ons/payumoney/
https://sitenol.com/payumoney-integration-errors-sandbox-production
https://stackoverflow.com/questions/23773892/sorry-some-error-occurred-while-integrating-payumoney-payment-gateway-in-test
Note: We are not responsible for the authenticity of these Articles regarding the solutions they provide but we are sharing them with you for your ease and convenience. Hope you can understand !
Best Regards