SQL Server Transactional replication failed due to snapshot agent failure
It sounds like you may have set Force Encryption on the instance.  In SQL Server Configuration Manager, you can see this setting (server-side encrypting enforcement) by expanding SQL Server Network Configuration and then right-clicking on Protocols for YOURINSTANCENAME, and selecting Properties.  You will see the option there to toggle Force Encryption, as well as a tab for Certificate config.



I am by no means saying to disable forced encryption (if that is indeed your problem, I'm guessing somebody set that for a reason), but you will need to ensure that the communication between those two is properly configure.  Here is a good KB article that seems to explain what you're running into.