I'm very confused by your message. The firmware is installed with a single click from the menu in T2Laser, you don't need to use notepad++ and I am not sure what the "messages" at the end of the lines means. You can't view a hex, it's compiled, you would need to go back to the Grbl source to see any messages as to what the code means.
It isn't even necessary to set the baud rate for uploading firmware, just the port. Then T2Laser takes care of everything else.
When you connect to use the machine the baud rate should be 115200, anything else with 1.1 firmware and you won't get a valid connect string and nothing will work.
You can't run UGS and T2Laser at the same time, they both need dedicated access to the port. This would certainly cause problems and errors.
I've run literally hundreds of millions of lines of g-code from T2Laser and never had the problem you described so I am certain the error is due to something other than software.