In order to optimize the runtime order of build jobs, Electric Make tracks historical information about job runtimes and relationships from previous builds in a schedule file. The file format is versioned, as the it may need to change to accommodate enhancements to the schedule optimization feature between versions of CloudBees Build Acceleration. If emake finds a schedule file with a version number different than it expects, it will print this message and ignore the scheduling information in the file. This will not affect the correctness or reliability of the build, but may affect performance since the schedule optimization feature will be disabled for that run. However, at the end of the build emake will write a new schedule file in the correct format for that version of emake. Subsequent builds will use the updated file, and this warning will no longer appear.
This warning may occur if you are switching between different versions of CloudBees Build Acceleration while running builds with the schedule optimization feature enabled, or after you upgrade to a new version of CloudBees Build Acceleration.