Hi
Timer and Backgroundworker are running in two different threads. So you cannot simply access the timer control from Backgroundworker. Can you please try the below code:
private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
this.Invoke((MethodInvoker)delegate()
{
timer1.Enabled = true;
timer1.Start();
});
}
NB: If your need is to just display blinking label, timer control is enough. There is no need of backgroundworker.
Regards
Dominic