```python
"Exception caught in handler - \"not enough values to unpack (expected 3, got 2)\": Traceback (most recent call last):
 File \"/opt/nuclio/_nuclio_wrapper.py\", line 143, in serve_requests
 await self._handle_event(event)
 File \"/opt/nuclio/_nuclio_wrapper.py\", line 397, in _handle_event
 entrypoint_output = self._entrypoint(self._context, event)
 File \"/opt/nuclio/main.py\", line 29, in handler
 shape, state = context.user_data.model.infer(image, shape, states[i] if i < len(states) else None)
 File \"/opt/nuclio/model_handler.py\", line 56, in infer
 self.config['hp'], device=self.device)
 File \"/opt/nuclio/SiamMask/tools/test.py\", line 152, in siamese_init
 z_crop = get_subwindow_tracking(im, target_pos, p.exemplar_size, s_z, avg_chans)
 File \"/opt/nuclio/SiamMask/tools/test.py\", line 88, in get_subwindow_tracking
 r, c, k = im.shape
ValueError: not enough values to unpack (expected 3, got 2)
```