Reading word docs etc

I have an ASUS TF tablet running on ICS.

Until yesterday I could receive emails with attachments and they would open via the Polaris. Today for some reason it treats any files received as attachments as unreadable with the apps on the tablet. Any ideas what I need to check or rest to enable this feature again. I have word files I want to open and edit with Polaris. I am not very technical so need an idiots guide to solving it.