Which version change was significant for the compatibility of Zabbix proxy and server?

The version change that represents a significant advancement in the compatibility between Zabbix proxy and server is version 6.4. This version introduced improvements in how Zabbix proxies communicate with the server, enhancing efficiency and stability. It included updates that allowed for more seamless integration and better handling of data between the proxy and the server, which is crucial for maintaining reliable monitoring across distributed environments. These enhancements help ensure that data collected by proxies is accurately and promptly relayed to the server, thereby improving overall system performance and reliability.

While earlier versions like 5.0 and 6.0 introduced important features and capabilities, the specific compatibility improvements that version 6.4 brought made it a critical milestone for users relying on proxies in their Zabbix environment. Version 7.0, while it may introduce new features, does not have the same emphasis on compatibility changes for proxy and server as version 6.4.