I’ve upgraded. Thanks for letting me know.
WordPress: Version 4.9.6 (in Multisite Mode)
EM: Version 5.9.3
EMP: Version 2.2.1
I was originally running the site under PHP 5.6.x. My webserver also has: PHP 7.0.26 and PHP 7.0.30 installed on the server. I tried all three versions (restarting the webserver service each time). I can install any version of PHP that you want us to try.