Minor Bug: importing two Subcircuits with MCUs

When dragging a second subcircuit with an MCU (e.g. Arduino Uno B) into the central panel a warning "Only 1 MCU allowed" is displayed. After clicking Ok the subcircuit element is imported, as if it is working - but (of course) it is not working, since the MCU is not included.

Maybe an alternative error message would be better: "Only 1 MCU allowed. Subcircuit is not functional." or the subcircuit should not be included.

Additionally, the error message seems in WIN10 not to be in the same "window range" as the main application or the property windows. It appears as separate task, when tabbing through the open windows (ALT+Tab).

As the multi-cpu feature is on the works, I probably will not solve this issue.

The first half sentence sounds great, thanks.