It looks like there are some icons missing in the Mint-X-Dark icons folder.
Copying the 32, 48 and scalable folders from /usr/share/icons/Mint-X/status/ to /usr/share/icons/Mint-X-Dark/status/ and rebooting seems to solve the problem.
It looks like there are some icons missing in the Mint-X-Dark icons folder.
Copying the 32, 48 and scalable folders from /usr/share/ icons/Mint- X/status/ to /usr/share/ icons/Mint- X-Dark/ status/ and rebooting seems to solve the problem.