The Ektron Windows Service for versions 9.3 and higher have made a switch to a secured connection by default. This change will lead to issues when older sites are on a CMS server that is running 9.3 or higher by default.
If there are issues syncing between two 9.3 sites there might be something within the network blocking communications in which case the following error occurs in the sync status window.
Object reference not set to an instance of an object.
The error could also be due to esync certificates expiring. If the object reference error only happens after 1/1/2019, see the following KB.
eSync security certificates expiring 1/1/2019
To get older versions of Ektron to sync between servers running 9.3 or higher the EnableNonSSLEndpoints field in the Ektron Windows Service(EWS) config file should be set to true.
EWS config path
<Drive>:\\Program Files (x86)\Ektron\EktronWindowsService40Ektron.ASM.EktronServices40.exe.config
<add key="EnableNonSSLEndpoints" value="true" />
Once changed stop and start the Ektron Windows Service and confirm that the service is shown as started in the event viewer. This will revert the sync to the pre-9.3 configurations, and will need to be implemented on all environments involved in a sync relationship.
If syncs between 9.3 sites are having trouble syncing there might be network settings that are blocking the communications. Setting the EnableNonSSLEndpoints to true as shown above can determine if the changes in sync standards are impacting the connection. If there is a change in behavior after switching this setting we recommend reviewing the network configuration and checking firewall logs for possible culprits.