Error: 'utf-8' codec can't decode byte 0xa1 in position 8: invalid start byte Total mass could not be calculated

[dashuaip]

Hello, when I tried to use the program to calculate the STL file volume, this error occurred:

r@ubuntu:~/STL-Volume-Model-Calculator-master$ python volume_calculator.py ./123.STL volume 
Error: 'utf-8' codec can't decode byte 0xa1 in position 8: invalid start byte
Total mass could not be calculated

I drew and exported the STL file in soliwork, and the graphics are very simple. How can I solve this problem?

[dashuaip]

This is an error displayed in the Ubuntu terminal.