It's irritating. Have re-downloaded and re-installed the app several times, all to no avail. Seems (vague, sorry) to occur if I've been working directly on a camera memory card plugged into a Kingston reader. This comes up on application re-start . . :
. . and won't go away while of course RT is not responding - catch 22!
Today, not even re-starting the computer fixes.
Any ideas? (apart from installing V4, buying a bigger computer, etc. ;-)