Sometimes, web services URLs change, in such cases, an error-sign will appear near the layer in the layers page. The example below shows what happens when renaming the parcels layer (at the publishing engine level: Geoserver level); and how you can solve this easily by changing layer data source.
The screenshot below shows that GeoGATE is recognizing the Parcels layer (the green icon appears on the layer).
In order to simulate the change the map service URL case; go to Geoserver and change the parcel layer name, so that its link changes (old name: parcels, new name: Parcels). Please refer to Publishing Spatial Data via web using Geoserver section for more information about layers publishing.
Now, the parcels layer service changed. Accordingly, GeoGATE will not recognize it and the red error icon will appear on the layer.
Now, click on Edit Connection button, and select the new layer (Parcels2).