Check your custom component for the selector which you are trying to use is not getting resolved. If u can add ur custom component code then we can help u out more
Whenever u create a keystore or truststore a node gets created in aeem .To change the password you nèed to delete previously created node in crxde and recreate through ui.
refer this one-https://stackoverflow.com/questions/31350548/resourceresolverfactory-getserviceresourceresolver-throws-exception-in-aem-6-1/31394583#31394583