Word won't open documents from external drive...

Hi everyone,

MS Word 2011 recently stopped opening all documents I have on my external hard drive (WD Elements). I says: "Word cannot open this document. The document might be in use, the document might not be a valid Word document, or the file name might contain invalid characters (for example,\ /)."

When trying to save a word document onto the external drive it says: "Word cannot save or create this file. The disk may be full or write-protected. Try one or more of the following: * Free more memory. * Make sure the disk you want to save the file on is not full, write-protected or damaged."

The strange thing is that I am able to see all the documents on the external drive and also I can open them in Preview. Also, the disk works perfectly fine with all other files like PDF, movies, photos, etc.

I'm not exactly sure what caused this problem but I have upgrated to OSX Lion very recently and also some days ago the external harddrive was "not ejected properly."

Could either of these things have caused this problem? If the disk was damaged it seems unlikely to me that all the other files still work fine and I'm still able to open the documents in Preview.

Any ideas on how to fix this issue? I hope I won't have to format the external drive.

Thanks a lot in advance for you help!

Kind regards.