All Users Errors and the White Screen of Death

I am getting the following error inside one of my WordPress websites attempting to access the list of all users at this url: https://demo3.customwpsites.com/wp-admin/users.php

The error Message:
“Fatal error: Unknown: Cannot use output buffering in output buffering display handlers in Unknown on line 0.”

If we go to another page in the WP dashboard and go back again, we get the following (or something very similar):

Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 358401 bytes) in /home/customwp/public_html/demo3/wp-includes/functions.php on line 3092

Here is what is on that line:

ob_end_flush();

found within this CSS:

function wp_ob_end_flush_all() {
$levels = ob_get_level();
for ($i=0; $i<$levels; $i++)
ob_end_flush();
}

I am not certain what is causing all of this however, in researching what I could, I was thinking it might have something to do with the memory allocation that can be adjusted within the php.ini file. So I created a new php.ini file and added it the root level of the site.

Unfortunately, I still have the error. Eventually, the more times we go back to the url in question, we do get the white screen of death indicating to me there is some sort of plugin conflict going on.

NOTE: the entire site works except for the all users link. We are able to work around by going into your admin styled area and access the approved users without any issues.

I am also using Gravity forms Add on User registration.

https://www.ads-software.com/plugins/new-user-approve/