Checked my install today and run pihole -up however its not able to complete due to a new dependency? php5-xml. I think this is the second time that I run the update since I moved to the Beta.
Manually trying to install php5-xml does not show any candidate for install.
Raspbian Jessie is end of life and not supported by either Pi-hole of the makers of Raspbian. You'll need to update to at least Stretch but best option would be Buster.
