Dear Ext.net
I am trying to build a multiupload button within a grid but when I drop files here, it returns error, and I found a potential bug ,
Please see the enclosed picture and the error line?Click image for larger version. 

Name:	2014-12-05 16_24_06-Developer Tools - http___localhost_55612_POPP_SampleReport_EditReport.png 
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Size:	63.1 KB 
ID:	16951
X.MultiUpload().Cls("mtupload").Button(b =>
{
// b.Add(X.ImageButton().Width (20).Height (20).Cls("btnupload").Text ("drop files here"));
b.Add(X.Button().Width(120).Cls("btnupload").Text( "Drop files here"));
}).Listeners(l =>
{
//l.UploadStart.Handler = "Ext.Msg.wait('Uploading...');"; l.UploadError.Fn = "uploadError"; l.FileSelectionError.Fn = "fileSelectionError";
l.UploadStart.Handler = "Ext.Msg.wait('Uploading...');"; l.UploadError.Fn = "uploadError";
// l.FileSelectionError.Fn = "fileSelectionError";

l.UploadComplete.Handler = "Ext.Msg.hide()";
})
.FileQueueLimit(0).AutoStartUpload(true).UploadUrl ("upload").UseQueryString(true).PostParams(p =>
{
p.Add(new Parameter("srid", "this.record.data.srid", ParameterMode.Raw, false));
p.Add(new Parameter("IssueId", "this.record.data.IssueID", ParameterMode.Raw, false));
p.Add(new Parameter("lineno", "this.record.data.lineno", ParameterMode.Raw, false));
p.Add(new Parameter("msgid", "this.record.data.msgid", ParameterMode.Raw, false));
})