Tried installing CE on a new MacBook laptop with High Sierra 10.13.6 and get the Error M061. Following the instructions in the error and selecting Allow under Security & Prefs does nothing. It will not accept the Allow button to be selected.
Thank you for reaching out to us and I apologize for the difficulties you've been experiencing. By chance do you have your Mac firewall enabled? I have spoken to other users in the past who were experiencing the same issue you've been having and we had success with temporarily disabling the Mac firewall. Once the firewall was disabled they were able to select 'Allow'.
If you need any assistance with temporarily disabling the firewall or this does not fixed your issue please feel free to contact our Customer Service at 877.479.1119 and we would be more than happy to assist you! We are available Monday-Friday from 8am-11:4pm EST and Saturday from 10am-5:45pm EST