Blank page after activation

Hi, after activation, I get a blank page in the admin section no matter where I go. I have to go in via FTP and rename the folder so that wordpress automatically disables the plugin and I can navigate the admin again. Is there any reason for this that you know of that could cause this? Please let me know. Also, I am using the multisite functionality it wordpress.

https://www.ads-software.com/extend/plugins/password-protect-wordpress/