We built a custom app to access Sage service. We installed a SSL certificate so that our external app can access Sage securely. We encountered some weird issues relating to HTTPS / SSL certificate.

1) First we installed a self-signed SSL certificate (as only our custom app needs to access the Sage) to a Windows Server 2019 standard (64 bits). After installation, it worked perfectly. On the 30th day however, the certificate stopped working. It shows connection closed by the server. We thought it was the self-signed certificate not working properly. So we purchased a 1-year SSL certificate from Digicert.

2) We installed the 1-year SSL certificate from Digicert to the server, it worked great initially. But again on the 30th days of installation. It stopped working. We have re-downloaded the certificate but still doesn’t work. The issues appears to be the Windows server. The connection was closed by the server on the 30th day.

Now we conclude it might be something to do with the server settings. Anyone knows what could trigger the closing connection behavior for our SSL certificate? It seems it was pre-scheduled event/settings the on the server that triggered this?