Non-static method BackWPup_Admin::admin_css() should not be called statically

Same problem.

BackWPup Version 3.7.1 on WordPress 5.4.1

The same issue

BackWPup Version 3.7.1 WP 5.4.1

@weindler
@russ-faurot
@lernerconsult
Thank you all for reporting it, we already aware of the issue and the fix will be included in the next update, for now, you can just ignore the warning, or replace backwpup/inc/class-admin.php with this one:
https://gist.github.com/cuongdcdev/267bff4e4a68b6d8409e18ab8a5b0ee7

I hope that helps!

Hi, issue still here in the last update

Same here: Issue popped up today. Deprecated: media_buttons_context is deprecated since version 3.5.0! Use media_buttons instead. in /home/rocketr6/public_html/wp-includes/functions.php on line 5152

Plugin deactivated until solution is found…

I have had this for a couple of months; not sure when it started. Everything is up to date.
Looks like the same message:
Deprecated: Non-static method BackWPup_Admin::admin_css() should not be called statically in /usr/home/web/users/a0026794/html/wp-includes/class-wp-hook.php on line 287