I am using MarkerCluster_compiled.js from github. But while the logic works, its graphics started failing from yesterday.
The problem seems to be caused by \"https:
Please be aware that the compiled version (https://rawgit.com/googlemaps/js-marker-clusterer/gh-pages/src/markerclusterer_compiled.js) is no longer available, as can be seen in this commit:
https://github.com/googlemaps/js-marker-clusterer/commit/c259d330cc2183e6751ff97ec5ade76e749e0188