

Try using :verbose nmap gc to find out what the shortcut is currently mapped to.
I don’t use mini.comment, but I assume it needs an operator after gc to for commenting. I have seen gcc used to comment out the line. Just wanted to make sure you are using the correct mapping.



Next time, try enabling display of whitespace characters through
set list. If I remember correctly, they can help distinguish between the Windows carriage return character and Linux end of line character.This may help for a quick overview.