Solutions to "**.grd is not a valid grid file" error when reading a GRD file into Surfer

The ".grd is not a valid grid file" error message indicates that you are selecting a GRD file format that is not supported in Surfer.  The GRD file extension is shared by a number of different grid file formats.  Alternatively, the file may not actually be a grid file. If you believe it is a supported grid file format and it is still generating the error, please zip and attach the file to a support request so we can take a look and determine what the issue is.

Another potential cause of this error is that you are attempting to access a file on a network that uses aggressive file locking.  Older versions of the Novell network operating system had the problem and Novell issued a patch.  Consult your network administrator or vendor for additional information. To work around the problem, copy the file to a local hard drive prior to opening it.