Diagnosis
The jar is likely stuck due to a vacuum seal created during blending, especially with hot liquids or overfilling. The powerful motor and Wave Action system can create a strong suction, locking the jar onto the base's drive coupling. It's not cross-threaded; it's a simple mechanical seal that just needs to be broken.
How to Fix It
First, unplug the blender. Grip the blender jar with both hands, not the handle. Apply steady, firm upward pressure while twisting the jar counterclockwise (lefty-loosey). If it doesn't budge, run warm (not boiling) water over the bottom third of the jar for 30-60 seconds. This gently expands the plastic jar base, breaking the vacuum. Dry the base thoroughly, then try the twist-and-lift motion again. You can also try tapping the sides of the jar base lightly with the handle of a wooden spoon to help jar it loose.
If That Didn't Work
If the warm water trick fails, place a few ice cubes in the jar and let it sit for a minute. The rapid cooling can contract the materials slightly and break the seal. As a last resort for a stubborn seal, carefully and briefly turn the blender on to its lowest pulse setting for one second. The sudden reverse jolt can sometimes dislodge it, but ensure the jar is properly seated and you are ready to unplug it immediately after.
Heads Up
Never use metal tools, pliers, or excessive force to pry the jar off, as this can crack the plastic base or glass. Avoid twisting the jar by its handle, as this can break it. Always ensure the jar and base are completely dry before reattaching to prevent future sticking.