Unsupported major.minor version 49.0

Today I replaced few jar files and got an "Unsupported major.minor version 49.0" when running my unit tests against the new jars. Immediately I realize that those new jar files are compiled using different version then the one I'm running on.


I'm still using JDK 1.4.2_11, it's old I know. But that's what my app server uses.

The new jars were build using java 5, so I switched the version to run the unit tests and that major.minor version part is gone.

If that's the only issue I have, my problem for the day would've been over and I would have move to the next thing on my list.