For the benefit of everyone….
My site is running on Cloud Linux which is designed to run previous versions of PHP SAFELY.
This is a PAID Linux because it is kept up to date with security patches.
I had to do this because it’s going to be a big job to update the site template to a version on PHP 7.x.
It’s really only the deprecated PHP that causes the problems.
Michael’s SubFolder Pro is running quite happily on Joomla 3.96 and PHP 5.6