Error message using AlignLib

[icbicket]

Following error message received on using AlignLib.Align on six SEM images, after adjusting images and hitting Enter:
Traceback (most recent call last):
File "/home/isobel/.local/lib/python3.6/site-packages/matplotlib/cbook/init.py", line 216, in process
func(*args, **kwargs)
File "/home/isobel/Documents/McMaster/PythonCodes/DataAnalysis/src/AlignPlot.py", line 48, in MoveImg
self.ShowImages()
File "/home/isobel/Documents/McMaster/PythonCodes/DataAnalysis/src/AlignPlot.py", line 29, in ShowImages
self.fig.canvas.draw()
File "/home/isobel/.local/lib/python3.6/site-packages/matplotlib/backends/backend_tkagg.py", line 10, in draw
_backend_tk.blit(self._tkphoto, self.renderer._renderer, (0, 1, 2, 3))
File "/home/isobel/.local/lib/python3.6/site-packages/matplotlib/backends/_backend_tk.py", line 80, in blit
photoimage.blank()
File "/usr/lib/python3.6/tkinter/init.py", line 3548, in blank
self.tk.call(self.name, 'blank')
_tkinter.TclError: invalid command name "pyimage70"