Dx bad class file magic (cafebabe) or version (0033.0000) with ADK14

Question

Since moving to ADK14, I have been unable to build new apks for release on my Windows 7 system.

Building fails with \"conversion to dalvik format failed with error 1

Answer 1

Upon reading the source of the dex tool, the problem here is that the class file is not within a version that it can understand. The version must be between 45-50 (major version) The version you're using here is 0033.0000 (0x33 in hex), which is 51 in decimal (the version number representing Java 7). This is not speculation on my part, I found this directly in the source code.

Following is speculation, and what solved my problem: I haven't figured out what you have to do to solidly confirm what class file version you'll get upon compiling with various options, but for me the problem was that my library had been compiled with Java 7. Since Android only supports Java 5 or 6, I simply recompiled in 6, and boom, solved.