I recently ran into this error when migrating between versions of eclipse (due to a reinstall ), specifically from helios to indigo builds. The problem occurs due to the project being compiled against a particular Java version specified in the eclipse settings. Then when using a newer version of eclipse one will get a . class compatibility error complaining .
The error message states to select “fix project in android tools” (access by right clicking on the project folder). This did not work for me however.
I checked the Java bytecode format in “Window/Preferences”, “Java/Compiler/Compiler Compliance Level” to make sure version 1.6 was set (the version I was building against). This also did not solve the problem.
I eventually solved the problem by rebuilding the project