File document viewer not working in Mx7.4

Hi All, I am building an app which requires a view page for some PDFs. The project was created in Mx 7.3 and the document viewer worked fine in that version, but since converting to 7.4 whenever you view the document it simply displays a message : invalid pdf structure. Does anyone know what causes this? or does the widget not work in 7.4 perhaps? The PDF can still be viewed through adobe, and I've even sent it as an attachment in an email which displays fine using outlook or gmail.  
1 answers

That could caused by a bug in 7.4. See:  A fix was released yesterday with 7.5.