( ! ) Fatal error: Cannot use isset() on the result of an expression (you can use "null !== expression" instead) in /var/www/www.diwanpress.com/wp-content/plugins/gutenberg/lib/class-wp-theme-json-gutenberg.php on line 602
Call Stack
#	Time	Memory	Function	Location
1	0.0001	225200	{main}( )	.../index.php:0
2	0.0002	227808	require( '/var/www/www.diwanpress.com/wp-blog-header.php' )	.../index.php:17
3	0.0003	245456	require_once( '/var/www/www.diwanpress.com/wp-load.php' )	.../wp-blog-header.php:13
4	0.0004	257648	require_once( '/var/www/www.diwanpress.com/wp-config.php' )	.../wp-load.php:50
5	0.0010	433608	require_once( '/var/www/www.diwanpress.com/wp-settings.php' )	.../wp-config.php:102
6	0.4358	51896224	include_once( '/var/www/www.diwanpress.com/wp-content/plugins/gutenberg/gutenberg.php' )	.../wp-settings.php:409
7	0.4358	51896408	gutenberg_pre_init( )	.../gutenberg.php:20
8	0.4360	51932944	require_once( '/var/www/www.diwanpress.com/wp-content/plugins/gutenberg/lib/load.php' )	.../gutenberg.php:73