ClickOnce application does not update or launch

I have a Windows Forms application that I have deployed using ClickOnce, but the users navigate to a network drive and double click on setup.msi instead of using a webpage to install it.

I 开发者_开发知识库have two users that have it installed and it's worked in the past. I did an uppate last week and now when the users try to launch the application the window that says "Verifying Application Requirements" pops up, and then when it disappears nothing happens. The dialog that is asking if it's OK to update never pops up.

The network people have verified that they have permissions on the network drive (though, I would expect an error message if this were the issue).

What could cause this to happen?

Have the users recently installed drivers for Kensington hardware (e.g. mice or tracballs)? There is a driver bug that causes ClickOnce applications to behave in a manner that's very close to what you're describing. Here's one discussion of the issue.

• Did you bump the publish version? (though, the publish wizard should do this automatically)

• Did you change anything - such as the assembly names?

• Did you mark the update as a mandatory update? (That is, setting the minumum required version equal to your new publish version.) If not, chances are some user clicked 'Skip' on the update, and the application won't try to update itself for another seven days. Those users have to uninstall their current application, and they have to manually install your new one - or wait a week.

If the published location is on IIS, make sure the IIS website working. You can do this by seeing if the ClickOnce Installer webpage works from the http hosted location.

I had this problem today. Published an update like I had dozens of times in the past -- turned out there was something wrong with the app pool in IIS. Changing the app pool (or restarting the web server) resolved the issue.

I had this problem because Windows was tagging the ClickOnce cache as having come from the Internet (and not from a site in the IE Trusted Sites zone). As long as you know that the app is safe, you can download Sysinternals streams.exe and run it like this from a command prompt:

streams.exe -s -d c:\Users\YourUserProfile\AppData\Local\Apps\2.0

This will clear all alternate data streams that tell Windows that the cached binaries came from the Internet, allowing the program to launch.

I have tried adding the ClickOnce source URL to my Internet Explorer Trusted Sites Zone, but that did not solve the problem for me.