Javascript error: SyntaxError: JSON.parse: unexpected end of data at line 1 column 1 of the JSON data

Question

I have a CS:GO betting website and when I try to go to the page to withdraw skins or something like that after I verify that i am not a robot using recaptcha I get this error:

Javascript error: SyntaxError: JSON.parse: unexpected end of data at line 1 column 1 of the JSON data

Here is the code :

function redeem(){
    var code = $("#promocode").val();
    $.ajax({
        url:"/redeem?code="+code,
        success:function(data){     
            try{
                data = JSON.parse(data);
                if(data.success){
                    bootbox.alert("Success! You've received "+data.credits+" credits.");                    
                }else{
                    bootbox.alert(data.error);
                }
            }catch(err){
                bootbox.alert("Javascript error: "+err);
            }
        },
        error:function(err){
            bootbox.alert("AJAX error: "+err);
        }
    });
}

Here is my syntax error:

SyntaxError: Unexpected end of JSON input
at Object.parse (native)
at Object.$.ajax.success (http://www.gamesnodie.com/template/js/offers.js?v=106:249:29)
at j (http://www.gamesnodie.com/template/js/jquery-1.11.1.min.js:1:27244)
at Object.k.fireWith [as resolveWith] (http://www.gamesnodie.com/template/js/jquery-1.11.1.min.js:1:28057)
at x (http://www.gamesnodie.com/template/js/jquery-1.11.1.min.js:1:85993)
at XMLHttpRequest.b (http://www.gamesnodie.com/template/js/jquery-1.11.1.min.js:1:90047)

Network tab results: http://prntscr.com/b1pao5

Answer 1

Please post in your question the JSON you are receiving from the server.

This issue could be related to a malformed JSON, or a wrong Header Content Type of your request, which actually should be as "application/json" as "Content-type" for JSON.

Answer 2

I solved the issue by generating a recaptcha key and adding it to the config file. After that the problem got solved.

Answer 3

Define dataType json in your ajax call and then you don't need to use JSON.parse().

function redeem(){
    var code = $("#promocode").val();
    $.ajax({
        url:"/redeem?code="+code,
        dataType: 'json',
        success:function(data){     
            try{
                if(data.success){
                    bootbox.alert("Success! You've received "+data.credits+" credits.");                    
                }else{
                    bootbox.alert(data.error);
                }
            }catch(err){
                bootbox.alert("Javascript error: "+err);
            }
        },
        error:function(err){
            bootbox.alert("AJAX error: "+err);
        }
    });
}