Cannot connect to cnc machine

Hi

I have been using Easel Pro with a 3rd party CNC using GRBL. I am now unable to connect to my CNC machine, I have checked the com port is correct and updated all the drivers. Checked anti virus and firewall, checked all wiring, changed usb lead, cleared browser cache but to no avail. Easel/machine were working fine when turned off last time but next day failed to connect. Cannot get Easel to connect again. I have also tried Estlcam and it works fine.

Anyone have a similar issue? Any help appreciated.

Usually restarting the pc fixes this unless its a browser setting blocking usb contol.
Google chrome seems to work best