I have design studio 15.0.6 (64 Bit) installed and it launches fine and I can create new applications, I can even connect data sources to the sample applications, this also works fine.
For some reason though I can't add components, they appear on the left of the screen and I can drag them, but when I drop them nothing happens. This is for every available component.
I found that I had previous installations (14.0.3 I think) but I removed this using the installation history screen.
Can anybody suggest anything for me to check?