ArcGIS API for Python を用いたディープラーニングモデルのエラー

ArcGIS API for PythonのSingle Shot Detectorを用いて画像分類の深層学習（トレーニングデータからの抽出）をしているのですが、トレーニングデータを学習するコードを入力した際に下記のようなエラーが生じてしまいます。
このエラーの意味が分かる方いましたら、ご教授させていただけないでしょうか？
コードはJupyter Notebookを使用しております。

Python
1ssd.fit(epochs = 5, lr = slice(float(1e-3), float(1e-2)))
2ssd.lr_find()
3ssd.fit(epochs = 5, lr = slice(float(1e-3), float(1e-2)))

Error
1TypeError                                 Traceback (most recent call last)
2<ipython-input-8-f5fcc504501f> in <module>
3----> 1 ssd.fit(epochs = 5, lr = slice(float(1e-3), float(1e-2)))
4
5~\AppData\Local\ESRI\conda\envs\arcgispro-py3-clone\lib\site-packages\arcgis\learn\models\_ssd.py in fit(self, epochs, lr)
6    177         =====================   ===========================================
7    178         """
8--> 179         self.learn.fit(epochs, lr)
9    180 
10    181     def unfreeze(self):
11
12~\AppData\Local\ESRI\conda\envs\arcgispro-py3-clone\lib\site-packages\fastai\basic_train.py in fit(self, epochs, lr, wd, callbacks)
13    170         callbacks = [cb(self) for cb in self.callback_fns] + listify(callbacks)
14    171         fit(epochs, self.model, self.loss_func, opt=self.opt, data=self.data, metrics=self.metrics,
15--> 172             callbacks=self.callbacks+callbacks)
16    173 
17    174     def create_opt(self, lr:Floats, wd:Floats=0.)->None:
18
19~\AppData\Local\ESRI\conda\envs\arcgispro-py3-clone\lib\site-packages\fastai\basic_train.py in fit(epochs, model, loss_func, opt, data, callbacks, metrics)
20     92     except Exception as e:
21     93         exception = e
22---> 94         raise e
23     95     finally: cb_handler.on_train_end(exception)
24     96 
25
26~\AppData\Local\ESRI\conda\envs\arcgispro-py3-clone\lib\site-packages\fastai\basic_train.py in fit(epochs, model, loss_func, opt, data, callbacks, metrics)
27     87             if not data.empty_val:
28     88                 val_loss = validate(model, data.valid_dl, loss_func=loss_func,
29---> 89                                        cb_handler=cb_handler, pbar=pbar)
30     90             else: val_loss=None
31     91             if cb_handler.on_epoch_end(val_loss): break
32
33~\AppData\Local\ESRI\conda\envs\arcgispro-py3-clone\lib\site-packages\fastai\basic_train.py in validate(model, dl, loss_func, cb_handler, pbar, average, n_batch)
34     47     with torch.no_grad():
35     48         val_losses,nums = [],[]
36---> 49         for xb,yb in progress_bar(dl, parent=pbar, leave=(pbar is not None)):
37     50             if cb_handler: xb, yb = cb_handler.on_batch_begin(xb, yb, train=False)
38     51             val_losses.append(loss_batch(model, xb, yb, loss_func, cb_handler=cb_handler))
39
40~\AppData\Local\ESRI\conda\envs\arcgispro-py3-clone\lib\site-packages\fastprogress\fastprogress.py in __iter__(self)
41     45         except Exception as e:
42     46             self.on_interrupt()
43---> 47             raise e
44     48 
45     49     def update(self, val):
46
47~\AppData\Local\ESRI\conda\envs\arcgispro-py3-clone\lib\site-packages\fastprogress\fastprogress.py in __iter__(self)
48     39         if self.total != 0: self.update(0)
49     40         try:
50---> 41             for i,o in enumerate(self.gen):
51     42                 if i >= self.total: break
52     43                 yield o
53
54~\AppData\Local\ESRI\conda\envs\arcgispro-py3-clone\lib\site-packages\fastai\basic_data.py in __iter__(self)
55     68     def __iter__(self):
56     69         "Process and returns items from `DataLoader`."
57---> 70         for b in self.dl: yield self.proc_batch(b)
58     71 
59     72     @classmethod
60
61~\AppData\Local\ESRI\conda\envs\arcgispro-py3-clone\lib\site-packages\torch\utils\data\dataloader.py in __next__(self)
62    635                 self.reorder_dict[idx] = batch
63    636                 continue
64--> 637             return self._process_next_batch(batch)
65    638 
66    639     next = __next__  # Python 2 compatibility
67
68~\AppData\Local\ESRI\conda\envs\arcgispro-py3-clone\lib\site-packages\torch\utils\data\dataloader.py in _process_next_batch(self, batch)
69    656         self._put_indices()
70    657         if isinstance(batch, ExceptionWrapper):
71--> 658             raise batch.exc_type(batch.exc_msg)
72    659         return batch
73    660 
74
75TypeError: Traceback (most recent call last):
76  File "C:\Users\tnyuk\AppData\Local\ESRI\conda\envs\arcgispro-py3-clone\lib\site-packages\torch\utils\data\dataloader.py", line 138, in _worker_loop
77    samples = collate_fn([dataset[i] for i in batch_indices])
78  File "C:\Users\tnyuk\AppData\Local\ESRI\conda\envs\arcgispro-py3-clone\lib\site-packages\torch\utils\data\dataloader.py", line 138, in <listcomp>
79    samples = collate_fn([dataset[i] for i in batch_indices])
80  File "C:\Users\tnyuk\AppData\Local\ESRI\conda\envs\arcgispro-py3-clone\lib\site-packages\fastai\data_block.py", line 544, in __getitem__
81    if self.item is None: x,y = self.x[idxs],self.y[idxs]
82  File "C:\Users\tnyuk\AppData\Local\ESRI\conda\envs\arcgispro-py3-clone\lib\site-packages\fastai\data_block.py", line 94, in __getitem__
83    if isinstance(idxs, numbers.Integral): return self.get(idxs)
84  File "C:\Users\tnyuk\AppData\Local\ESRI\conda\envs\arcgispro-py3-clone\lib\site-packages\fastai\vision\data.py", line 349, in get
85    return ImageBBox.create(*_get_size(self.x,i), *self.items[i], classes=self.classes, pad_idx=self.pad_idx)
86  File "C:\Users\tnyuk\AppData\Local\ESRI\conda\envs\arcgispro-py3-clone\lib\site-packages\fastai\vision\image.py", line 337, in create
87    bboxes = tensor(bboxes).float()
88  File "C:\Users\tnyuk\AppData\Local\ESRI\conda\envs\arcgispro-py3-clone\lib\site-packages\fastai\torch_core.py", line 70, in tensor
89    res = torch.tensor(x) if is_listy(x) else as_tensor(x)
90TypeError: can't convert np.ndarray of type numpy.object_. The only supported types are: double, float, float16, int64, int32, and uint8.
91