Why does OpenLayers display red tiles for USGS map?

Question

I am trying to display the USGS national map via OpenLayers: http://viewer.nationalmap.gov/viewer/

OpenLayers is able to display the USGS map. However, when I zoom in, the tiles turn red. Could someone explain how to fix this?

Is there a USGS restriction on zoon levels?

Thanks

Answer 1

Try adding this to your code:

OpenLayers.IMAGE_RELOAD_ATTEMPTS = 3;

Ref Ref2

Answer 2

Try opening the red tile to see if there is an error message in them or change your EXCEPTIONS to application/vnd.ogc.se_inimage in the WMS parameters to see the error message in the image that is returned.