My XF account upgrade suddenly stops working. It worked until last Wed. It uses authorize.net gateway for payment. The error I can capture is this one ----CURL ERROR---- The certificate issuer's certificate has expired. Check your system date and time. I'm confused on what cert has expired? My site www.quantnet.com uses a cert that expires in 2019. @eva2000 can you please run some ssl query and see what is wrong? The date time on my server seems correct.