Server suddenly unable to bind

Hi, I'm currently using Netcode for GameObjects version 1.1.0 and the Unity Transport library to set up a Server - Client architecture. Before integrating the MRTK UI/tools into the project, the Server had no issues binding but I'm not sure MRTK is to blame for the Server now failing to bind. The IP and Port of the Network Manager have remained the same at 127.0.0.1 and 7777. I've read a couple posts detailing that changing the IP or Port in the Network Manager resolved the "Server failed to bind" error though this solution has not worked for me. I also came across a post where deactivating the inbound rule of the Unity Editor in Windows Defender Firewall resolved the error, and once again this was not the case for me. Has anyone encountered a similar predicament?

 

Did you try rebooting?

 

Thank you @CodeSmile. This resolved the issue.