Plugin config page showing white screen

Hi there,

white screens in most circumstances are due to a lack of PHP Memory.
Can you check the memory you have allocated on your server

Already added php memory limit in wp-config.php

define('WP_MEMORY_LIMIT', '128M');

Still the same issue.

1. Go to Tools > Site Health.
a. check there are no errors
b. check the Info > Server settings and provide a screenshot of them.

2. Disable ALL plugin aside from GP Premium
Try to visit the problem page again.

There is no option for site check because we are using old wordpress version.
Also we don't using any other plugin except GP Premium.

Which version of WP are you using ?

We are using wordpress 4.9.17 version

wow... ok.

Check with your host:

a. How much memory is allocated on the server.
NOTE: define('WP_MEMORY_LIMIT', '128M'); only sets the WP limit. It won't change a server level allocation.

b. Enable debugging and check for any server errors when the white screen occurs

define( 'WP_DEBUG', true );

Added this but there is no any error, Only a white screen again ;(

Wordpress also upgraded to 5.1.13

Can you check the physical memory on the server, and also check the PHP Version.