design review fails to open a previously saved dwf

[Anonymous]

I have a dwf file which was opened, marked up and previously saved. When trying to re-open this file the following error message occurs;
Your current version of Design Review does not support files of this type.
Has anyone had this happen before and if so, is there a fix?

[Anonymous]

What version DR do you have? The error message is very specific about the
failure... .

--
Dean Saadallah
http://LTisACAD.blogspot.com
--

[Anonymous]

Design Review 2009 service pack 1 installed

[gbales]

Tried to open a .dwf created in autodesk design review 2012 with autodesk design review 2013, but

it will not open in either version and gives the following error:  "Your current version of Design Review

does not support files of this type".  I tried changing filetype to .ZIP and open, but would not open. 

Any ideas on how to get this file open?  It opened fine for a week or so after it was created in ADR 2012,

but now will not open in ADR 2012 or 2013.