DIAGNOSIS Ice chunks have fused the basket to the auger blades or the basket guide rails are misaligned.
FIX Do not force it. Unplug the machine. Let it sit off for 30 minutes to let ice melt slightly. Gently twist the basket left and right while pulling straight out. If stuck due to a large ice block, use a hair dryer on low, cool setting to blow warm air into the ice storage area for a minute.
IF THAT DIDN'T WORK Look inside with a flashlight. The auger might be mispositioned, blocking the basket path. Manually rotate the auger by reaching in and turning it clockwise until it clicks into the home position.
HEADS UP Never use a knife or sharp tool to pry the basket. You will crack the plastic or damage the auger sensor. This is a design flaw with many countertop units if ice sits too long.