“Invalid signature file” when attempting to run a .jar

Question

My java program is packaged in a jar file and makes use of an external jar library, bouncy castle. My code compiles fine, but running the jar leads to the following error:

Answer 1

It's possible that two different signers mess up java mind.

Try removing META-INF folder from jar, adding manifest and signing JAR again, it helped me: http://jehy.ru/articles/2013/12/13/invalid-signature-file-digest-for-manifest-main-attributes/