RStudio suddenly stopped showing plots in the plot pane

Question

RStudio is not showing the generated plots in the plot pane anymore. Instead they open in a separate file with the name "Quartz". Here\'s my session info.:

Answer 1

It could be because graphic device are already on .

To find indices of open devices:

dev.cur()

To close devices:

dev.off(i)

where i is index of device to be switched off.