Javascript: For loop stops and I dont know why

I have made an loop to convert my two dimensional array into an json string. My array (called columns):

[["Application1", "11106.serpkpoe.com", "11109.example.com", "11102.exampleserver.com", "11105.exampleserver.com" "Database, AFPUOR(KNAJKLD)", "Database, UOQZRNJ(LKUJD)" ],
 ["Application2", "44407.blabla23.com", "11106.exampleserver.com", "11104.exampleserver.com", "Database, POJPR (OIUOLWA) ", "Database, UIAHSD (JJJQEP)" ],...]

I wrote this code to convert the array to json string like this:

for (var i = 0; i < columns.length; i++) {
    data[columns[i][0]] = {
        Server: [],
        Datenbank: []
    };
    console.log(columns[i][0]);
    console.log("1")
    for (var j = 1; i < columns[i].length; j++) {

        console.log(columns[i][j]);
        if (typeof columns[i][j] == 'undefined'){
        console.log("----------------undefined break")
            break;
        }
        if (columns[i][j].match("Datenbank")) {
            data[columns[i][0]]['Datenbank'].push(columns[i][j]);
            console.log("----------------Datenbank gefunden")
        } else {
            data[columns[i][0]]['Server'].push(columns[i][j]);
            console.log("----------------Server gefunden")
        }
    }
}

The code executes it very well at first but after some columns it just stops and doesnt output values anymore.

it looks like this then:

{
   "Application1":{
      "Server":[
         "Exampleserver1",
         "Exampleserver2",
         "Exampleserver3",
         "Exampleserver4",
         "Exampleserver5",
         "Exampleserver6",
         "Exampleserver7",
         "Exampleserver8",
         "Exampleserver9",
         "Exampleserver10",
      ],
      "Datenbank":[

      ]
   },
   "Application2":{
      "Server":[
         "ExampleserverXYZ12",
         "ExampleserverASB22",
         "ExampleserverACS32",
         "ExampleserverABC42",
         "ExampleserverKLJ52",
         "ExampleserverPOI62",
         "ExampleserverKLJ72",
         "ExampleserverTZU82",
         "ExampleserverUOI92",
         "ExampleserverIL102",
      ],
      "Datenbank":[

      ]
   },

This goes on but for some reason after a few objects it doesnt write the data anymore and then it looks like this:

   "Application2":{
      "Server":[
         "",

      "Datenbank":[

      ]
   },

But in the array there is information and I have no idea why it doesnt push them into the json object?

Thank you for your help :)