This question already has an answer here:
I don't know what I pressed, but this happened before.
- I can't undo or redo in object mode but it still works in edit mode.
- When I move an object to another layer I need to press an "OK" button.
- Can't use the lower half of the left toolbar in object mode, it is grayed out.
Here are a couple pictures:
What is causing this strange behavior?