RadMaskedEditBox: how disable auto select?

Hello, Eusebio,

According to the provided brief information, it is not clear which mask type that you use and how your RadMaskedEditBox is set up.

You can handle the GotFocus event and manage the text selection:

this.radMaskedEditBox1.GotFocus += this.RadMaskedEditBox1_GotFocus;
private void RadMaskedEditBox1_GotFocus(object sender, EventArgs e)
{
    this.radMaskedEditBox1.SelectionLength = 0;
    this.radMaskedEditBox1.HideSelection = false;
}

In case, you need further assistance it would be greatly appreciated if you can provide more information about the case that you have on your end.

If you need further assistance do not hesitate to contact me.

Regards,
Nadya
Progress Telerik