Plugins are not updated from Dashboard > Updates

Issue 1:

Getting a lot iof these errors in server log

2018-10-19 12:03:00 Error AH01071: Got error 'PHP message: PHP Fatal error: Uncaught Error: Call to undefined function get_header() in .../wp-includes/theme-compat/embed.php:13nStack trace:n#0 {main}n thrown in .../httpdocs/wp-includes/theme-compat/embed.php on line 13n'

Issue 2:

Can’t bulk update plugin. After bulk updating plugins, a message shown that all plugins were updated suscsefully. After rechecking for updates, same plugins shown in the list again:

(22)Invalid argument: AH01075: Error dispatching request to :, referer: