This is just a warning and can be ignored, it should not affect the ability to open a tractogram.
If you are using an M1/M2/M3 mac and cannot visualize .tck files, even after following the instructions on Issues with pseudotube rendering on Apple M1 macs, I suspect there is a mistake in your config file.
Can you copy-paste the output of the terminal command:
cat ~/.mrtrix.conf