Hi Hanh, Which version of Ferret are these machines running? A Google search for the error message px_get: Assertion `offset >= 0' failedshows that this is an error with large-file access. Some versions of Ferret previous to the most recent ones were built with OPeNDAP libraries that did not have large-file support. Ansley nguyen@xxxxxxxxxx wrote: Hi everyone I've retrived data from ERA40 and tried to use it simply as follow:use air.79_89.ncand then this message appears:ferret: lnetcdf/lposixio.c:269: px_get: Assertion `offset >= 0' failed. AbortI've tried to do the same in another machine, it worked well. Any idea? Thanks for your help Hanh |