Doing a .Response.Write off of the current HttpContext in an ApiController may misbehave in Internet Explorer.

Internet Explorer cannot display the webpage.

...is the error message you are apt to see in Internet Explorer even as it works in Chrome and Firefox.

 
 

ourContext.Response.Write(whatever);

...is not enough.

 
 

ourContext.Response.Write(whatever);
ourContext.Response.Flush();
ourContext.Response.End();

...is better. This worked for me in IE8 and above.