Problem with INS
In some case you might have entered INS webhook URL incorrectly at 2Checkout dashboard > integration webhook/API setting. Make sure you have followed the instruction provided in 2Checkout setting docs page.
Firewall & security plugins
Another possible reason could be a firewall blocking the connection. It won’t be possible to guess without checking server logs but in some cases, firewalls like ModSecurity installed in your web hosting server also might block INS response. In this case please do kindly check with your web hosting system administrator. Also consider de-activating security plugins like Wordfence, Securi and other security plugins if you have installed it.
SSL stands for secure sockets layer. Protocol for web browsers and servers that allows for the authentication, encryption and decryption of data sent over the Internet. Valid SSL is required to make successful handshake between our plugin INS webhook URL & 2Checkout INS response server. Make sure to check your website SSL quality to make sure that you have properly installed the SSL certificate in your EDD store.
While going through the 2Checkout documentation we were not able to find the information related to the SSL Cipher suite that 2Checkout INS doesn’t support for it’s INS handshake. If you are sure about firewall & SSL quality do kindly contact 2Checkout seller support to troubleshoot the problem.
If nothing works for you do kindly contact us via our support page along with the debug log data.