This is a new fault as far as I know. There have been problems in parts search on Win10 when some of the windows patches have failed, but not file open as far as I know. If you don't try and open a file (which I know isn't useful 
) does it continue to run? If so you might try clicking on help->check for updates and see what happens. Fritzing tries to check github for new parts at every startup, and sometimes (especially if it got interrupted) the parts database gets corrupted but deleting the user files usually corrects that as long as it completes correctly on the reinstall (it does pause for a longish time on startup while it makes does the update and there is no progress bar or indication it is doing anything, you just have to wait and it will eventually complete). Its also possible that the latest patch set has broken something (although it hasn't for me on Win7). The failure (a windows popup that Fritzing has stopped working) is typical of a corrupted parts database though (that is usually the c:\users\username\AppData\Fritzing\roaming\Fritzing directory), I believe there is a Fritzing bug that an exception doesn't get handled somewhere if the database gets corrupted (or in my case when I screw up making a new part, which shows up as corruption in the parts database ) and that is how it shows up, but deleting the two directories and starting again (after correcting the error in the new part) has always fixed it for me. I take it that the debug console doesn't say anything useful when you try and open a file and it fails? Other than that I'm out of suggestions, hopefully someone else may have an idea.
Peter