zero-size array

I use a linux server without a graphical interface to run python gen.py. Sometimes the following error will appear, and sometimes it will not appear. Does anyone know the reason for this?
i have seen #228 ，but I don't know where to modify.Hope to get your reply！thanks！

Traceback (most recent call last):
File "/data01/home/scy0798/run/xrzhao/SynthText-python3/synthgen.py", line 660, in render_text
regions['homography_inv'][ireg])
File "/data01/home/scy0798/run/xrzhao/SynthText-python3/synthgen.py", line 525, in place_text
im_final = self.colorizer.color(rgb,[text_mask],np.array([min_h]))
File "/data01/home/scy0798/run/xrzhao/SynthText-python3/colorize3_poisson.py", line 440, in color
lx, ly = np.min(loc[0]), np.min(loc[1])
File "<__array_function__ internals>", line 6, in amin
File "/data01/home/scy0798/miniconda3/envs/SynthText3/lib/python3.7/site-packages/numpy/core/fromnumeric.py", line 2880, in amin
keepdims=keepdims, initial=initial, where=where)
File "/data01/home/scy0798/miniconda3/envs/SynthText3/lib/python3.7/site-packages/numpy/core/fromnumeric.py", line 86, in _wrapreduction
return ufunc.reduce(obj, axis, dtype, out, **passkwargs)
ValueError: zero-size array to reduction operation minimum which has no identity