Please set the real path of your server first with the command. By setting the real path you can not update or install in another place (what you surely do..) do not use another command, use this one:
force_install_dir c:\Path\To\KF2Server\
c:\Path\To\KF2Server\ being the path to the server folder, change it according to your installation.
Then use also the validate parameter to verify all the files in the server folder, you can alternatively delete the steamapps folder inside the server folder to force the files validation.
app_update 232130 validate
You should be good.