Failed to import Python module 'scour'
There is a bug in Inkscape that causes this error when attempting to save an optimized SVG file, and it even happens when "scour" is correctly installed.
To solve the problem, add Inkscape as a PPA instead of installing from official repositories:
sudo add-apt-repository universe sudo add-apt-repository ppa:inkscape.dev/stable sudo apt-get update sudo apt install inkscape
Failed to import Python module scour
On my system I also tried to solve the problem by installing scour using the following command in a terminal:
pip3 install scour
This did not work, so the error message is probably misleading.
The precise error message encountered when attempting to save the .svg file was:
Failed to import Python module 'scour'.
Please make sure it is installed (e.g. using 'pip install scour' or 'sudo apt-get install python-scour') and try again.
Details: No module named scour
The error message is inaccurate both because "scour" is installed on the system (using pip3 install scour), and because the "python-scour" package does not exist when trying to install it via apt install python-scour.