Can not add or remove appointments in pb native calendar, help?

Can anyone help me? Can't add new or remove old appointments from native calendar. Also lost all my contacts about a week ago.

How much space do you have left on the pb? Swipe down from the main screen and select the Gear, Then select About, then on the right, tap the drop-down menu and Select hardware.

Had you installed any new apps just before this occurred?

Are you syncing with some other calendar?

I have 9.3gb left and no new apps.

I have 9.3 gb. No new apps. When I swipe down the left top there are 2 boxes...PlayBook local with check and Gmail with my Gmail address but no check. I don't think I am syncing at least not intentionally.

Try these:

To fix an issue, try these in order:

Restart using the Battery Icon and press Restart

Press and hold the Power button for 10-15 seconds. Then leave it for 20-30 seconds and see if it restarts.

To REBOOT:
Press and HOLD all three keys for about 10 - 20 seconds: PowerOn, VolUp and VolDown. Start with the PowerButton. Keep holding past the 3-choice options screen. If you hear a shutter type sound, you've taken a Screen Shot and probably missed the PowerButton.