I recently upgraded php and moodle at the same time on our development site, from php 5.6->7.1 and then moodle 3.1.5+->3.3.5+
After upgrading php moodle server notice stated 7.1 was not supported for moodle 3.1. The site still worked and I proceeded to immediately upgrade moodle from 3.1 to 3.3 but I was wondering if there are any risks or downsides to briefly operating moodle 3.1 with php 7.1 in maintenance mode?
I was thinking about re-trying the whole upgrade process in our development site only this time upgrading moodle first and then php.
I just did a little research on the differences between 7.0 and 7,1, for the most part it was not major syntax/feature changes but the focus on backend performance so I guess that's why I noticed no issues.
Moodle 7.1 is not supported for Moodle 3.1. If the release notes say it's not supported then you can be *sure* that there are problems.
There were a whole bunch of problems reported in the tracker, see MDL-55120
Thanks for the info Howard, I will be sure to upgrade moodle from 3.1 to 3.3 before upgrading php from 5.6 to 7.1