Razorpay payment gateway module
I am using WHMCS for several years now.
The major issue is the lack of inbuilt payment gateways which are popular in India.
Many of them have external WHMCS modules, but almost all of them don't work properly or have bugs.
WHMCS has only one Indian payment gateway: CCAvenue - Which every customer hates.
I am sure India must be a decent market for WHMCS.
I request the WHMCS team to bring native support for payment gateways such as: Razorpay, PayTM, Cashfree, PayUmoney, Instamojo.
Razorpay is currently most popular in India and their WHMCS module on Github has several issues which they do not care about. Same goes with the others above.