I came across this issue as well, it's nothing to do with the CMV app, but is an ArcGIS server issue.
The resolution which worked for me is:
Set ArcGIS Server Account's Windows default printer's default page size to a size as large as or larger than the page layout that is being exported. For example, if the map document is a tabloid size (11 x 17), set the default printer's default page size to 11 x 17 or larger. If setting the printer to the exact size of the layout page, check that the orientation (portrait or landscape) also matches the layout to be exported. The easiest solution is typically to install a plotter driver, as these have the largest page sizes available by default. Microsoft Windows ships with many plotter drivers available through the Add Printer wizard. No download is necessary.