Explanation: Wordshark and Numbershark are programmed (mainly) in a computer language called “Java”. For our programs to work, they need the computer to understand this language and be able to use it.
For Windows PCs, this is rarely a problem, as these load the Windows Java Runtime Environment (“JRE”) bundled with our programs. Contact Support if you see this error message on your Windows PC
Mac computers, however, rely on a special Mac-permitted “Java Runtime Environment (JRE)” which is frequently changed*. Mac Operating System Updates may delete the JRE if it is not used and/or updated. Recent versions of Mac OS X come without JRE (to make the OS X slightly smaller, so faster to download and install) so many Mac users need to download JRE and install it on their Mac.
The message “Unable to load Java Runtime Environment” means that the Mac computer cannot load JRE, either because it is out of date or (more usually) because it has not yet been downloaded and installed. It can also happen after the computer OS X has been updated, e.g. to 10.14 Mojave from 10.13 Maverick.
*Java is updated several times per year: At Oct 19 the latest is Java version 8, Update 231
What to do about it?
1. Download Java 8 from https://java.com/en/download/help/mac_install.xml (Notice the “Download” link on the red title bar, but first read the instructions further down the page – you may need to scroll down to see these)
Install it, using the on-screen instructions. More advice is given here: https://java.com/en/download/faq/java_mac.xml
3. If your Mac OS X is 10.15 Catalina, which includes various extra security features, you will need to read additional advice from JRE publishers Oracle: https://www.oracle.com/technetwork/java/javase/using-jdk-jre-macos-catalina-5781620.html
Wordshark/Numbershark usually then works, as your computer is now able to load the “Java Runtime Environment for Mac”.