First I get two "access denied" error messages, then a "I/O error" message. Everything as Windows message boxes. I'm not sure a part is from the OS via some developer debugging stuff. But it's simply a bit much.
Steps to Reproduce:
1. Open Writer
2. Export document as PDF
3. Open PDF in Acrobat Reader
4. Export document as PDF again and try to overwrite the file
Three message boxes with some general error message.
Only one error message.
User Profile Reset: No
Tests were done with my Windows dev master build, but I guess this will happen just on Windows, because of the file locking / open semantics of the OS.
*** This bug has been marked as a duplicate of bug 53530 ***