Internal Server Error CGI program sent malformed or too big

Error 500, Internal server CGI program sent malformed or too big

OR

(500) Internal Server Error Error 500: Internal Server Error CGI program sent malformed or too big (>16384 bytes) HTTP headers: [] URL: config.cgi/key?_=1699484758

In IIS settings, Disable CGI Impersonate User. The default is set to enabled (TRUE). Change this to FALSE. The error 500 should no longer occur.

If using DirWeb.exe, the error may be related to ENS on the Unitysync server.