I wish I could give more help, but there's a limit to what I can do without making a billable project out of it and that's not why I'm here. You do seem to have a nasty one though.
Offhand, I would suspect one of 2 things, though:
1. You are attempting to embed a ZIP-format objects in an HTML webpage. HTML is text-only, so retrieving and unzipping a binary object transferred via a text channel isn't likely to end up happy. I don't really think this is is, because I don't think that there's any way that the unzip part would happen automatically anyway, but I could be wrong.
2. You have a corrupt ZIP/jar file on your server. This is more likely the case, although again I'm not sure where this is coming from. I have had issues where when my WAR was on a network share, Tomcat couldn't properly unzip and deploy it, though.
Customer surveys are for companies who didn't pay proper attention to begin with.