Published Application Won't Launch On Other Computers

I've been working on a piece of software for a few weeks now and I've got to the point where I'm publishing it and testing it on other computers, namely my colleague's. We're both working on the same network and have similar permissions for our accounts, but for some reason the application will launch on my account but not his.

We've tried using the same computer and just changing accounts, but that won't work either; he still isn't able to launch the published application.

I receive the standard "[x] has encountered a problem and needs to close. We are sorry for the inconvenience." message.

What is baffling me is that we've tried previous versions on his computer and they worked just fine. I can't think of any changes that I've made that would suddenly stop the application from running.

A few extra pieces of information: the application has a splashscreen, which displays for a few seconds before the error message crops up. In this time, the program is supposed to check if certain files and directories exist and, if not, create them. It also changes file attributes. These files exist in a directory we are both able to access and both have permissions to change. It also changes and sets some variables within the program itself, but I don't see that being an issue. It is able to catch exceptions of type IOException and InvalidOperationException (which was being thrown when a computer didn't have access to the intranet).