I've uploaded Grbl 1.1 on a Mega 2560. Library installed with no problems. However, the grblUpload program build showed some warnings - one related to the serial port.
I do not get the Start Message in the Serial Monitor. In fact nothing happens. I set the baud rate to 115200 as specified. Am I missing something?
Other info:
PC - HP EliteBook 8760w
OS - Windows 10
Arduino IDE 1.8.12
What made you think that your question has anything to do with the working of this Website and Forum? I have suggested to the Moderator to move it to the Motors and CNC section.
This sort of carelessness makes unnecessary work for the Moderators.
Did you load the 2560 / mega version of GRBL as you may come across issues if you did not.
AFAIK 1.1 is for UNO's only.
Finding the correct and most recent version for the MEGA is a right pain and took me a few days searching and testing before I found a suitable one.
Even that was quite old so I ended up just using it as a test rig.