Invalid signature file digest for Manifest main attributes

Today i run into error

Invalid signature file digest for Manifest main attributes
while running my java web start applet. I wondered for a while and finally found the reason - yesterday I modified my .pfx key for signing applet, but manifests in jars merge with each other - so I really had jar with invalid digest. To **fix it**, I just had to remove META-INF folder from all my jars, add them manifest again and re-sign them. You can remove it with any archiver - for example, with 7-zip.