Created Unassigned: callbackoncollecteddeligate detected error in R,Net [163]

i have got the callbackoncollecteddelegate was detected error in r.net when i run the following code
private void inputCSVToolStripMenuItem_Click(object sender, EventArgs e)
{

REngine engine = REngine.GetInstanceFromID("RDotNet");

try
{
engine.EagerEvaluate("dataset1<-read.table(file.choose(), header=TRUE, sep = ',')"); error is indicated at this code in this line

}


catch{
MessageBox.Show(@"Equation error.");
}
how can i solve this problem