Steven Zahm@ Edward
I was investigating this further…
Look what I found in the Maps Marker changelog for version 3.12 released on 3/25/2014:
https://www.mapsmarker.com/docs/changelog/free/
“improved option “Deregister Google Maps API scripts enqueued by third parties” to prevent re-enqueuing of scripts by also deregistering them”
This option when enabled, if I read it correctly, actually deregisters the scripts the template requires to run when enabled because it uses the Google Maps API.
This option appears to be off by default. I suggest turning it back off since there was no conflict prior to their latest update.
Their setting can be found on their plugin settings page. Search for “Deregister Google Maps API scripts enqueued by third parties”
After you turn this off I suspect the two plugins will work together again.
Hope this helps! Let me know.