This is probably a stupid question. For some reason the copy command suddenly started only allowing to select one object. If I click copy and select a line, then select a second line, it selects the second line and de-selects the first line. It does allow me to copy multiple objects using a crossing window. But I cannot individually click multiple objects as it will deselect the previous object with each new click. I'm sure this must be a simple setting that got unchecked somewhere.