KDE has some awesome cursors. Too bad then, when you try to use them outside of KDE, some things become broken, like the resize cursors, or even the fact you need to change the system cursor theme. So until the Ubuntu team does something about this, here is more-or-less what you need to do to resolve all of your cursor issues.
Do note, I have these issues in MATE, this does not apply to Mint KDE far as I know, and may not apply to other desktop environments that make sense of KDE's filename schema for the oxygen cursors.
Different cursors depending on application or privilege (single user)
If you find that after you select your cursor, you encounter the issue of your cursor not consistent between windows, perform the following command;
Terminal: System-wide theme selection
Code: Select all
sudo update-alternatives --config x-cursor-theme
Resize cursors not appearing properly
There is no easy fix for this I had came up with yet, but you can put this series of commands into an .sh file, make executable and duplicate it into every theme affected;
Terminal: Symlink for compliant cursor naming
Code: Select all
ln -s size_fdiag top_left_corner
ln -s size_fdiag bottom_right_corner
ln -s size_bdiag top_right_corner
ln -s size_bdiag bottom_left_corner
ln -s size_ver top_side
ln -s size_ver bottom_side
ln -s size_hor left_side
ln -s size_hor right_side
After all of that work, you should have more-or-less a fully-functional cursor theme.