Bootstrap Spinner Model is Removing Vertical Scroll Bar

[hybrisser]

I have radio buttons on page for different insurance plans. On click of any radio button, I do a back-end process. Meanwhile, I want a spinner to load till the time backend process is completed. The code works fine like this:

Without Spinner Model:

		$(".insuranceSelection").on("click", function() {
		    $.ajax({
			 type: "POST",	
			 url  : "/insurance/plans",
			 async:true,
			 data : {
				 insurancePlan : insurancePlan
		 	 },
		 		error : function(response, status, msg) {
		 			console.log("error \n" + "Sorry an error has occurred please try again");
		 		},
		 		success: function(response) {
		            $("body").html(response);
		        }     
		 	});
	});

But if I add a spinner model, the spinner loads. But when the backend process is completed, the vertical scroll bar is removed from the page . I can see an error in chrome logs that Uncaught SyntaxError: Unexpected token <

With Spinner Model:

	$(".insuranceSelection").on("click", function() {
		 $('#spinnerModal').modal({
	            backdrop: 'static',keyboard:false, show: true
	          });
		    $.ajax({
			 type: "POST",	
			 url  : "/insurance/plans",
			 async:true,
			 data : {
				 insurancePlan : insurancePlan
		 	 },
		 		error : function(response, status, msg) {
		 			console.log("error \n" + "Sorry an error has occurred please try again");
		 		},
		 		success: function(response) {
		            $("body").html(response);
		        }     
		 	});
	});

PS: This error does not come if I remove spinner model from js.

Request you to help asap.
Thanks in advance.