Search (e.g. https://wiki.parabolagnulinux.org/index.php?title=Special%3ASearch&search=mips) gives this error:

Database error

A database query error has occurred. This may indicate a bug in the software.

In error log:

PHP message: 
PHP Warning:  is_executable(): open_basedir restriction in effect. File(/usr/bin/php) is not within the allowed path(s): (/srv/http/wiki/:/usr/share/pear) in /srv/http/wiki/includes/Wiki.php on line 655
PHP message: PHP Notice:  Uncommitted DB writes (transaction from DatabaseBase::query (WikiPage::pageData)). in /srv/http/wiki/includes/db/Database.php on line 3944

https://bugzilla.wikimedia.org/show_bug.cgi?id=56269 has a similar error, suggests running update.php which fixed it here once. It also shows that this message is caused by a different error, I haven't found what it is.