I'm not a computer person so these instructions left me worried about tackling them in this manner as first of all, I had no idea what ReadyNAS was or what that entailed. Fortunately, I still had soem warranty left on my Mac Book Pro so I called Apple support and they taklked me through an easier way that solved my problem. My problem began when I had to power down my Mac Book Pro to regain control and I am assuming it may have been in a timed backup when this happened and I never noticed it.
Anyway, briefly here is what the Tech took me through that go my time machine backing up again.
Enter Time Machine System Preferences as follows:
1. Click on <Time Machine> icon in upper right (clock with arrow surrounding it)
2. Click on <Open Time Machine Preferences>
3. Click on <Select Disk> in upper right of the pop-up window.
4. Now click on the Time Machine listed at top under Backup. It should then be highlighted.
a. An option should now appear shown as <Remove Disk>
b. Click <Remove Disk> which will leave only the time Capsule listed under Available.
5. Close out and then Click on <Time Machine> icon in upper right (clock with arrow surrounding it)
6. Select <Backup Now> and it should backup with no more problems.