This often happens when either: 

1. The modality is no longer sending data to a local routing device, due to network or DICOM Target configuration errors.  

2. The OmniRouter has lost connectivity to either the modality or the Internet.  First thing you should verify is that you can pull up our website and see if you getting to the Intenet.    If you know how - you should try to "ping" the modality or have the modality ping the router. 

3.  The IP of the routing PC has changed.   If the PC running the omnirouter has DHCP IP address configuration - it can change its IP and the DICOM Target information in the Modality configuration will need to be modified.  we highly suggest using dedicated and/or long lease IPs. 

In most cases if Internet is working - restarting the machine running the omnirouter and verify its up and listening when the system starts.