Seems like the problem I'm experiencing is erratic ... but seems
related to needing to wait until the document is entirely loaded.
There is a status message about "virus checking" and then an animation
is active for perhaps 10-20 seconds. If I try to "refresh" the links
with right-mouse-button "update link" before this is all done, then I
get the message:
Error! Not a valid filename
and the file is corrupted.