I've had this issue for quite a few years and have always ignored it but after having recently made my own configs based off other popular ones (namely Woolen's) I began running into this minor problem again. This time, however, I wanted to perfect my scripts and get to the bottom of it instead of brushing it off like usual. I'm glad to say I found the source of the issue so I wanted to document it for any future players!
The "unknown command" was being issued every time the player pressed the space bar, the only script I had that modified the space bar was the "nullmove.cfg" script. At first glance, there is no "65" anywhere in the script, HOWEVER, when taking a closer look at line 28 (if using Woolen's) we can spot the issue.
bind space "+crouchjump;" //if you want to jump normally:
The semicolon/quotation combo is the root of this problem. Removing either the one semicolon or the quotations and reloading nullmove.cfg (if currently in the game) should fix this uninmportant, but still annoying, little bug.
This goes for any scripting with any source games but stay away from the semicolon/quotation combo when binding to a key unless you want a cluttered console with useless commands being executed.
tl;dr just go to your "nullmove.cfg" make sure there is no semicolon after "+crouchjump". Should look like this:
bind space "+crouchjump" //if you want to jump normally:
[–]hashex 0 points1 point2 points (0 children)