Summarize this article in one sentence.
A blinking red light is a common problem with Ninja Blenders. Your blender will not work if the red light is blinking. To fix this problem, first check to see if the lid is locked. The blender will not work unless it is closed and locked. The blender is not locked until it has been pushed all the way down on the container. If the lid is locked, but the red light is still blinking, look at the arrows on your blender. There should be a white arrow on the lid and handle. These arrows need to be aligned for the blender to work. Move the lid until the white arrow on the lid aligns with the arrow on the handle. Then, check to see if the red light has stopped blinking. If it has, you can use the blender. Another potential reason for a blinking red light is if the pitcher is not properly aligned on the base. If it has been aligned correctly, it should be able to rotate. The pitcher will not easily rotate if it has not been placed properly on the base. Remove the pitcher and place it back on the base again to check if this is the problem. If the red light still does not go away, call Ninja Blender customer service for advice.

Summary:
Check to see if the lid is locked. Make sure the white arrows on your blender are aligned. Fit the pitcher on the base of the blender.