Cron not run for days - php fatal db connection

A bit weird but I was checking the php modules I had and some had gone missing?!?!?!
I went through the php modules required on the installation instructions on nextcloud documentation and typed php -m to list the ones on my machine, found the following had gone so re installed them then reboot.

  • php-gd
  • php-mbstring
  • php-mysql
  • php-xml

Though I had to do phpenmod mbstring to get it going again.
Seems to be working now. Hope this helps others.