Problem

Some customers will try running their agents with old JAVA versions after upgrading Bamboo and the agents will fail with:

java.lang.UnsupportedClassVersionError: com/atlassian/bamboo/agent/installer/AgentInstaller : Unsupported major.minor version 52.0"

Solution

Add the minimum JAVA version needed to run the agent main process into the Supported platforms - Atlassian Documentation document.