That's a very large file for InDesign. Do you have a lot of pasted or embedded graphics?
There's a good chance there is a problem with that particular file. Save a copy for backup, then try an export to .idml/.inx to clean it up. See Remove minor corruption by exporting
It amy also be a problem with a font, or a cross-reference, if you are using those. See Troubleshoot fonts | Mac OS X
The Remove minor corruption by exporting post worked.
I am running Windows 7 for anyone who may experience this issue.
Yes I do have a lot of graphics. Not sure how to tell if they are embedded or pasted. I actually though you could only add embeded graphics which could be part of my file size issue if there is a distinct difference.
Fonts are all the same in all my chapters.
Currently have no Cross-References.
If the export worked, it's not a font or cross-ref issue.
The best way to add graphical content is to use File > Place... and create a link to an external file This allows you to keep the ID file small and to reuse the same linked file in many places withthe ability, if necessary, to edit the external file and update the links wherever they appear.
Pasting images embeds the data for the entire image into the file and they are very difficult to edit if it becomes necessary.
.idml removes image previews and old change information, and maybe swatches (never checked). The previews are regenerated whenthe file is reopened. A Save As will also remove old change info, so I'm not sure just what was removed to reduce the file size unless your export was done after several sessions of editing using only a regular save.