Shamim's Plugins

It seems your theme uses z-index too high.
Are you comfortable to edit php code? If yes then add zindex: 9999, in front-end-pm-pro > pro > includes > class-fep-pro-to.php line 271 after width: ‘250px’,
If you are not comfortable to edit, give me ftp access so that i can add for you.

No other plugin will be changed.

Please full backup your website then let me know.

i am glad i could help you.
I am visiting China now and it is 3:15 am. still i am awake to assist you.
i always try to assist everybody (free or pro), you can see i also write code for my free users also (though my PRO support also does not include write custom code).
If you uncomfortable to edit code you can tell any developer, most of the time developers will assist you. This situation might not arise if you could tell me to assist you to add code in your website.

Have a pleasant day.

Best regards
Shamim

didn’t you tell them that you had added this code before this things happen?
All they had to to is remove this code from where you added and add again in appropriate location, nothing else.

Please access your website and remove that code from where you added. Then activate all your plugins and your theme.
Then let me know. I will add that code again in appropriate location for you.

This code is tested before giving you.
So either you php version is less then 5.3 or you had added this code in wrong place.
i can assist you if you give me your cpanel or file manager access.

assuming your php version 5.3+
Add following code in your theme’s functions.php (child theme’s if any)

add_filter( 'fep_eb_email_legends', function( $legends, $post ){
	$legends[ 'sender_username' ] = array(
				'description' => __('Sender Username', 'front-end-pm'),
				'where' => array( 'newmessage', 'reply' ),
				'replace_with' => ! empty( $post->post_author ) ? fep_get_userdata( $post->post_author, 'user_login', 'id' ) : ''
				);
	return $legends;
	
}, 10, 2);

Then go to Dashboard > Front End PM > Settings > Emails. use {{sender_username}} to send username in emails.

your theme should allow admin-ajax.php. There should be any option or any other way to allow this call.
Please contact your theme author.