The bit isn't fully seated in the quick-release chuck. The chuck only accepts 1/4" hex accessories or 1" bit tips.
- First, place the forward/reverse button in the lock-off (center) position or remove the battery pack.
- Firmly push the bit into the chuck until you feel and hear it click into place. It should be fully seated.
- To remove, grasp the bit and pull it straight out.
If that didn't work, inspect the chuck and the bit. The bit's hex shank might be worn or dirty, preventing a good grip. Try a different, clean bit. If the new bit also falls out, the internal hog ring in the chuck may be worn or damaged.
Heads up: Always ensure the tool is locked off or disconnected before changing accessories. A wrench or key left attached to a rotating part can cause injury.