I get an weird error on export

Sometimes when I export pdf or image i get this error...

Error: Supplied Data is not a valid base64-String jsPDF.convertStringToImageData at Object.x.convertStringToImageData (jspdf.min.js?2.8.2:23) at Object.x.addImage (jspdf.min.js?2.8.2:23) at Function.v3l.nN (flexmonster.js:9) at Function.v3l.cG (flexmonster.js:9) at Function.v3l.cR (flexmonster.js:9) at flexmonster.js:9 at flexmonster.js:9

 
 
What would cause this.  should i be doing something when I export this out.  I overrode the export functionality when I export excel, image or pdf.
 
here is my code...
 

function exportPDF(whichTab) {
var currentTitle = document.getElementById('customLabel').value;
switch (whichTab) {
case "Person":
{
personFlex.exportTo('pdf', {
header: currentTitle
});
} break;
case "Crash":
{
crashFlex.exportTo('pdf', {
header: currentTitle
});
} break;
case "Vehicle":
{
vehicleFlex.exportTo('pdf', {
header: currentTitle
});
} break;
default:
{
//do nothing
} break;
}
}
function exportImage(whichTab) {
var currentTitle = document.getElementById('customLabel').value;
switch (whichTab) {
case "Person":
{
personFlex.exportTo('image', {
header: currentTitle
});
} break;
case "Crash":
{
crashFlex.exportTo('image', {
header: currentTitle
});
} break;
case "Vehicle":
{
vehicleFlex.exportTo('image', {
header: currentTitle
});
} break;
default:
{
//do nothing
} break;
}
}
function exportExcel(whichTab) {
var currentTitle = document.getElementById('customLabel').value;
switch (whichTab) {
case "Person":
{
personFlex.exportTo('excel', {
header: currentTitle
});
} break;
case "Crash":
{
crashFlex.exportTo('excel', {
header: currentTitle
});
} break;
case "Vehicle":
{
vehicleFlex.exportTo('excel', {
header: currentTitle
});
} break;
default:
{
//do nothing
} break;
}
}

Start your code here

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