Can you get the existing web page to run on PHP 5.6? If so, you can uninstall PHP 7.0 and install PHP 5.6.
Another option is to install ProcessMaker in Docker or a virtual machine. See:
https://codeyourdream.com/blog/how-run- ... ing-docker
It is possible to install a second version of Apache and PHP on the same machine. Bitnami does this and uses a different port number, so it doesn't conflict with the existing installation of Apache using port 80. See:
https://wiki.apache.org/httpd/RunningMu ... eInstances
You can also configure different virtual hosts to use different versions of PHP with fast-cgi. See: http://blog.servergrove.com/2011/08/22/ ... on-apache/
I haven't tried any of these solutions, so I can't help you.
Amos B. Batto ♦ ProcessMaker Technical Documentation Writer & Forum Manager ♦ Cofounder of ILLA (http://www.illa-a.org)