When trying to sign a jar file, you get:
Jarsigner: Certificate chain not found for: DeploymentRuleSet.jar. DeploymentRuleSet.jar must reference a valid KeyStore key entry containing a private key and corresponding public key certificate chain.
You can get the Certificate chain not found error if you put filepaths in the jarsigner command line switches. To fix this, put all the files you are using with the jarsigner switch in the working directory (the directory you are running the command from in the command prompt – i.e. The file path to the left of where you type in the command prompt).
Sometimes you can get this error randomly, try starting the whole process again (recreate your jar file from scratch and use a simpler password – no special characters).