Cannot Edit Word Files in Contribute 4

[elwebby]

For the last couple of years, our users (and myself) have been able to
edit Word files in Contribute 4. We would click the Choose button,
select DOC file and say Open file. The file placeholder page would
display in the Contribute browser and the file would open in a Word
window. You could edit the file, save and close the file in Word and
then Publish the file in Contribute.

Now, when I Choose a DOC file, the file opens in Word as Read Only. A
file placeholder page does not appear in Contribute. I cannot edit the
file and then publish it to my site.

What made this start working incorrectly??