Rich- So it turns out that this is a server side problem. You can see it by inserting the following url into your web browser. http://colossus.dl.stevens-tech.edu/thredds/dodsC/fmrc/NYBight/NYHOPS_Forecast_Collection_for_the_New_York_Bight_best.ncd.asc?date This may take some time to fix. So as a temporary work around, you can prefix your urls with [noprefetch]. So for example, use [noprefetch]http://colossus... What is happening is that by default, the netcdf c library prefetches small variables from the server. One of these is date, and that is failing so it looks like the xpos is failing but it is really something else. [reminder to me: see if I can improve error reporting in this case]. p.s. I have moved this to the netcdf java support because it is a server side problem. =Dennis Heimbigner Unidata Ticket Details =================== Ticket ID: NRA-789780 Department: Support netCDF Java Priority: Normal Status: Closed