Why does OpenFileDialog delay a WinForms application on a specific machine?

Question

I have a WinForms application deployed to multiple computers in the same office. Until this day, all users in the office used the application without problems and used OpenFileDialog to select files to import. One machine had many updates for other applications and now freezes when our application tries to show OpenFileDialog. It shows a fine OpenFolderDialog; although I could not try SaveFileDialog. To repeat, it worked last week, our application was not updated, but this week it hangs on one machine, while it works on all other machines in the office.

This machine has another .NET application installed, and I confirmed that OpenFileDialog opens without problems in another application.

Any ideas as to why OpenFileDialog will freeze on the same machine? Any ideas how to fix this? We could try to reinstall without knowing the reason, but I decided it was better to investigate why this did not happen again.

Answer 1

This computer may have been connected to a network resource in the past that is no longer available. OpenFileDialog can wait for a response from a network resource, which will take several minutes to time out.