In your url you told Maps that you had a callback named initMap that you wanted it to call. But you have no such function. So you should not be surprised that there's a complaint.
If you don't need to call the callback, remove that portion of the url.
I have identified where problem is but don't know what the exact reason is.
First, I created a new CSHTML page and tried.
The same result.Test disappeared and Map did not get displayed.
Next, instead of using the existing css (namely site.css) with entry I removed its reference and created a brand new CSS (namely Map.css) and gave it's reference.
It works fine this time and loaded the map.
Below is the Map.css
Below is the site.css (the last line has entry for #Map)
As I said ,the map displayed only on creating a new cshtml page with new css reference .
The above cshtml with the above big css does not work .However the new cshtml page with just the map div and reference to new small css (map.css) works fine.I am not sure what is the exact css problem.
But I think thats not a possibility because site.css starts with giving background image to the page and if I comment that line background image won't show up. So it is taking the background image surely from site.css
Below is the code for top most part of site.css.(The complete code for the file I had pasted few posts above ):