For some reason the project file can't be uploaded, see screenshot instead:
The green LED is blinking at the same rate as the frequency from signal generator, despite that the opamp is not powered. When opamp is removed the LED is off.
I run crumb under proton in Linux.
This weekend I tried the same sim under Windows natively and it's same behaviour. Tested a buzzer in place of the led which gives audio instead of light (at higher frequency than ~10Hz). To remove one rectifier diode will turn the output off.