ClickOnce Deployment Error: different computed hash than specified in manifest

We were deploying to 2 servers using the same URL, with the routers load-balancing between them. Deploying to the 2 servers resulted in differences between the manifest files on each server, and the error. What worked was to deploy to only one server, and then copy the application folder to the other server.

You need to regenerate the application manifest. This happens when you change file contents and do not update your manifests accordingly.

Mage.exe MSDN Docs