InDesign CC cannot use Master Page Text Frames
If, like me, you like taking the time to set up one set of Master pages and then using the frames throughout the document - you'll have found out that you are unable to input text or images into those master frames. Initially my solution was to use those existing master frames as a skeleton over which I could input other usable frames. However, it turns out those frames were locked to a certain extent (I don't understand why they would be locked as default). There is also a simple fix to open them up.
On your master Page, simple press Shift+CMD and click on the desired frame that you would like to open. Bingo.