Have you made any changes to the computer recently? Did you add any new languages to your operating system and/or spell check application? Here are some things to check:
1. Make sure you are up to date on all of your security updates from Windows.
2. Make sure you are up to date on all of the updates for flexi.
3. Make sure your windows firewall is on.
4. If the path of the file (i.e C:\Jobs\File.ai) is longer than 255 characters, it will throw a buffer overrun error.