Jqgrid - when clicking on a row - expand sign is now visible

Question

I encountered something strange and I cant figure out why it is happening. When selecting a row the expand sign is disappearing. my example:

and the example in the Jqgrid tutorial site is as following:

As you can see, the expand sign is visible.

Here is my code for the grid:

$("#jqGrid").jqGrid({
    data: gridData,
    //editurl: 'clientArray',
    datatype: "local",
    page: 1,
    colModel: [
        { label: 'Flow Run Id', name: 'FlowRunId', key: true, width: 65 },
        {
            label: 'Run Status',
            name: 'RunStatus',
            width: 25,
            formatter: statusFormatter,
            align: 'center'
        },
        {
            label: 'Run Notes',
            name: 'RunNotes',
            width: 80,

        },
        {
            label: 'Start Date',
            name: 'StartDate',
            width: 40,
            formatter: "date",
            align: 'center',
            formatoptions: { srcformat: "ISO8601Long", newformat: "d/m/Y H:i:s A" }


        }, {
            label: 'End Date',
            name: 'EndDate',
            width: 40,
            formatter: "date",
            align: 'center',
            formatoptions: { srcformat: "ISO8601Long", newformat: "d/m/Y H:i:s A" }
        }

    ],
    viewrecords: true,
    width: 1100,
    height: 550,
    rowNum: 20,
    subGrid: true, // set the subGrid property to true to show expand buttons for each row
    subGridRowExpanded: showStepRunChildGrid, // javascript function that will take care of showing the child grid

    pager: "#jqGridPager"
});

$("#jqGrid").trigger("reloadGrid");

any ideas why its happening? didn't find anything on the web.

Answer 1

Had missing the file ui-icons_f7a50d_256x240.png (got an error in the run Console in my browser). Added the file to my project and now its ok.