Magento 2.1.3, Omise payment module issue. Need assistance in enabling the instalment payment.
Our shop is using Magento 2.1.3 with the CED Multivendor extension and few others. We are using Omise payment module for our payment system. Currently, we are only offering CC payments and Bank Transfers. Due to high requests from shoppers we are looking to enable the instalment payment method also. Normally the instalment payment option is easily enabled via dropdown but on our site, there is no section for instalment payment, it only shows CC payment. We tried updating the Omise module but that made things worse because of several conflicts with other code. We are getting this error after updating
([RuntimeException] Source class \Magento\Payment\Gateway\ErrorMapper\ErrorMessage for Magento\Payment\Gateway\ErrorMapper\ErrorMessageMapper generation does not exist.)
and the Omise module just disappears from Payment Method but CC payment still works but no instalment payment.
We asked Omise for help but they couldn't do it because we are using 3rd party extensions. We asked CED Commerce for help since they helped set up the store initially a few years ago but they have been ignoring our requests for months now. So we are reaching out to Magento experts on this forum if they have spare some time to look into the issue and help fix it or if anyone had similar issue can guide how to solve it.