Nagios-/Icinga-Portal

I am running Nagvis 1.5 and every time I try to upload a background image i get this error "'document.shape_add.image_file' is null or not an object" at line 1098 in WuiCompressed.js. I am assuming this is just a declaration issue but I am not sure what or where to put it. The background image still uploads but this error keeps coming up and is getting annoying.



Here is the coding from where the error is occuring.

function check_image_add() {
if(document.shape_add.image_file.value.length == 0) {
alert(printLang(lang['firstMustChoosePngImage'],''));
return false;
}



Any help would be appreciated.

When I installed NagVis it was the most recent nightly build which I installed within the past couple weeks.