Executable JAR Not Working? Fix the Common Errors

Executable JAR won't run? Fix 'no main manifest attribute', 'could not find or load main class', version errors, and double-click doing nothing.

First: Run It From a Terminal

"no main manifest attribute"

"Could not find or load main class ..."

"UnsupportedClassVersionError"

"NoClassDefFoundError" / Missing Dependencies

Double-Click Does Nothing At All

Summary