IssueTracker

Have you looked at using the Asynchronous Loading method https://developers.google.com/maps/documentation/javascript/tutorial#Loading_the_Maps_API ?

Example 1. Just trying to attach your gmaps script.
If you open the developer console, you will see that gmaps init script is loaded, but "getScript("https://maps.gstatic.com/intl/en_us/mapfiles/api-3/9/8/main.js");" line isn't working, there is no new script in the document after document.write.

Example 2. Trying to use callback parameter. Init is loaded, main javascript file is loaded too. But not working, exception screenshot is in attach.