This error was first found in this thread: https://forum.image.sc/t/sciview-cannot-install-on-fiji/46900/13
However the error is independent of sciview.

To reproduce the error:

1. Create a directory with a nonstandard character (to match the original forum thread, use ’ e.g. ~/IJ/non’standard/Fiji.app)
2. Create a new Jython script in Fiji and save it within this newly created directory
3. Try to run the script

The following error occurs:
image