Hi MikeT,
I don't have that "maven" EA. However, I can assist you with advise to make your EA workable with MT4.
First, if you installed correctly the EA in the "expert advisors" folder you will find an image with the EA's name " In the "Navigator" section of your MT4 platform.
If affirmative... the next step is to go to "Tools", "options", "expert advisors" and check the following are ticked:
-----Enable Expert Advisors
-----Allow live trading
-----Allow external experts imports
Then, to attach your EA to a chart you have to:
Go back to "Navigator", expert advisors and right click your EA , a menu will pop up... click "attach to chart" and...is done. You should see a smiley face -"top right" section of your chart.
The top section of the platform's toolbar has the "expert advisors" image, make sure that is green. (mean is enabled for trading)
If you click again , changes to red (mean disabled for trading).
Let me know if you require further assistance with MT4.
Cheers