I'm not an expert but it seams like a db table crash?
WordPress database error: [Incorrect key file for table './xnitepro_wp632/wpxbfubk_wpforo_profiles.MYI'; try to repair it]
UPDATE wpxbfubk_wpforo_profiles SET online_time = 1517395848 WHERE userid = 1
This is a conflict between two plugins?
Warning: Cannot modify header information - headers already sent by (output started at /...../...../...../wp-includes/wp-db.php:1399) in /...../...../...../wp-content/plugins/live-template-editor-client/includes/lib/class-ltple-client-session.php on line 337
(dots are replacing the full path)
Both errors are displayed together
I must mention that class-ltple-client-session.php suggests of using session functionality... could that get in conflict with online stats -- (how many users were online - my setting was 1 minute, changed it to 60 minutes a couple of hours ago)
This is not a conflict. This is hosting service MySQL server issue. The MySQL database table is crashed.
Try to optimize and repair wpxbfubk_wpforo_profiles table using this instruction (hosting > cPanel > phpMyAdmin):
Thank you @robert I will contact my colleague tomorrow and review/apply your suggestion.
Best regards,
Dan N