Shamim's Plugins

Please let me know following.
1. Did you use this plugin before starting this issue?
2. Do you have messages (messages between users) from previous version?
3. Check database and see if there any database table name start with PREFIX_fep_ where PREFIX if your database table prefix. if yes, let me know how many and what are they.
4. Do your set database user in wp-config.php have permission to create database table?

Can you send the website link again.

Ok, I will process your refund.

can you give me access to your website so that i can try? If yes, please send using https://www.shamimsplugins.com/sensitive-information/

If anyone in this thread still having this issue please create a separate topic.

I sent you a test website credentials to your email address to test reply. Let me know.

You can use fep_filter_read_receipt_individual as you already wrote (can change $time variable to something else) and fep_filter_read_receipt like following

add_filter( 'fep_filter_read_receipt', function( $output, $receipt ){
	return implode( '', $receipt );
}, 10, 2);