Shutter seems to work like normal after killing it from Terminal;
$ killall shutter -9
and even tested by calling Shutter from the CLI and successfully takes a screenshot without turning screen black with just mouse cursor. This is only a temporary fix measure when it plays up. I've added screenshot here with a bunch of errors it throws out from starting by command line
EDIT UPDATE ***
Shutter seems to work like normal after killing it from Terminal;
$ killall shutter -9
and even tested by calling Shutter from the CLI and successfully takes a screenshot without turning screen black with just mouse cursor. This is only a temporary fix measure when it plays up. I've added screenshot here with a bunch of errors it throws out from starting by command line