After loading a model when conduction single predictions, there is a list index out of range issue. The issue is located in foundation.py file, specifically line 120 (else [self.items[i_] for i_ in i]) which assumes batch input.

Input code:
! [ -e /content ] && pip install -Uqq fastbook
import fastbook
fastbook.setup_book()
from fastai.vision.all import *

learn = load_learner('export.pkl')

learn.predict(img)

Error output:

IndexError Traceback (most recent call last)
in
----> 1 learn.predict(img)

20 frames
/usr/local/lib/python3.9/dist-packages/fastcore/foundation.py in (.0)
118 return (self.items.iloc[list(i)] if hasattr(self.items,'iloc')
119 else self.items.array()[(i,)] if hasattr(self.items,'array')
--> 120 else [self.items[i_] for i_ in i])
121
122 defsetitem(self, idx, o):

IndexError: list index out of range