Hi,
attached is a minimal dataset to reproduce this. The csv file begins with two comment lines, both starting with "#" (as usual).
If I try to import the data in visone, the option to drop the lines beginning with something (here: #) does not work. Just test it to see how it messes up the preview window.
I have the latest visone version (2.27.1) running on a Linux Mint.
Best,
Kimmo