Image Stacking Help

[Rhys_SSD]

Here's the error:
Maximum supported image dimension is 65500 pixels
Traceback (most recent call last):
File "/home/pi/Documents/Rentokil CFC/Dev/Image Attach Vertical Stack.py", line 43, in <module>
imgs_comb.save('/home/pi/Documents/Rentokil CFC/Dev/trial.jpg')
File "/usr/lib/python3/dist-packages/PIL/Image.py", line 1728, in save
save_handler(self, fp, filename)
File "/usr/lib/python3/dist-packages/PIL/JpegImagePlugin.py", line 734, in _save
ImageFile._save(im, fp, [("jpeg", (0, 0)+im.size, 0, rawmode)], bufsize)
File "/usr/lib/python3/dist-packages/PIL/ImageFile.py", line 495, in _save
raise IOError("encoder error %d when writing image file" % s)
OSError: encoder error -2 when writing image file

So it's trying to say that image is too big.
Not sure why it works OK with the first line of code.
Is the way I'm breaking down the for loop creating another dimension maybe?

Rhys