Dropbox files causing Indesign, Word and Excel to crash

If we try to open any file contained in our dropbox folder - the application instantly hangs and crashes.

The is the same for applications like Word and Excel and also Indesign when 'placing' a file.

You can open the files by clicking on them directly in Finder - but by opening them from the application - the app crashes.

Dropbox said the latest Yosemite update (10.10.1) would fix this - but it clearly has not.

Does anyone have any advice please of what to do - or even just the support that you are suffering too!

Thank you.