WordPress MultiSite Installation

I’m currently looking for REAL ESTATE plugin to discover and review.
Upon downloading and the installation went fine until I clicked on “network activate” using NETWORK ADMIN control panel… I did it twice thinking it was just a fluke in my network.

This is the error I was getting…
“Warning: Use of undefined constant AUTH_COOKIE – assumed ‘AUTH_COOKIE’ (this will throw an Error in a future version of PHP) in C:\xampp\htdocs\wordpress\wp-includes\pluggable.php on line 806
Sorry, you are not allowed to access this page.”