“Cannot modify header information”

Unfortunately, the most recent update of WordPress seems to have a conflict with MK Simple Backups. the “Notice: undefined variable” was already reported, but mine has, in addition to a couple of these, a number of other errors.

There are three “Warning: Cannot modify header information” errors, one “Notice: add_submenu_page was called incorrectly” and one “Deprecated: get_bloginfo was called with an argument that is deprecated”.

Concerning the “Deprecated” error, it states that “siteurl” should be replaced with “url”. It also says that “siteurl” has been deprecated for a long time, so I don’t think changing it will adversely effect websites that are not completely up-to-date. Also, the two “Notice: undefined variable” errors are on line 49 of mk-simple-backups.php.

I have disabled the plugin for now, as I do not need it on a daily basis anyway, but once the errors are fixed, I will definitely reactivate. The website I used this plugin on is a very small and simple website, so I consider this backup plugin to be the most suitable. Thank you for your time. ??