I am a software developer and have a .Net program being used by a large number of clients. To install the program on the clients computer we use Microsoft's ClickOnce installer. We used this installer to provide a minimally intrusive install of our program, that didn't require being an admin user to install. The program also uses the ClickOnce installer to obtain updates. We do updates at least once a month. Once of our clients installed Norton 360 and since that install, we have been getting an error that one of the files has been corrupted and the updater did not complete. This client has about 50 users and it randomly affects their users. We are not identifying a pattern, only that the entire office updated to Norton 360 about 8 months ago, which is about the time the errors started happening. The problem is easily fixed if we wipe out the manifest and force a full install. I just wanted to see if anyone else is having this issue, or if this is a known issue. We run Norton 2010 in house and don't have the problem.