can't work with demo project package

Dear all,

as I should receive my first project package soon, I wanted to try my hand at working with one such package and used a demo project package that I downloaded along with Studio 2011. However, after importing and opening the package, I receive the following message "The file was created using a file type definition that does not exist on your system (Word 2007 v 1.0.0.0). The following functionality will be restricted or unavailable: Saving Verification QuickTags Preview". Consequently, I can't work with it. I've tried all kinds of things I could think of to get rid of the message, including

- adding *.docx and *.doc, respectively, into Project Settings > Filetypes > Microsoft Word 2000-2003 > 'File dialog wildcard expressions' and Project Settings > Filetypes>Microsoft Word 2007-2013 > 'File dialog wildcard expressions' and

- opening the project package through Notepad++ and changing all instances of docx to doc, but to no avail. 

As far as I know, I can't open the docx file alone that comes within the project package, which would enable me to save it as a doc file (which seems to be a usual workaround for many error messages in Studio). Strangely enough, I can work with Office 2007 documents without any problems using the Open Document and Create Project pathways. By the way, how come it says Word 2007 v 1.0.0.0 when normally it's Word 2000-2003 v 1.0.0.0 and Word 2007 v 2.0.0.0? Is something wrong with my Office software? To be honest, I guess it's either Studio or the demo project package that's causing the problem. This issue hardly ever seems to get raised by fellow Studio users, since I've found only a single question on the internet addressing the same issue (and with no proper reply) so I can't even try others' solutions. 

Any ideas?

Thanks