Attempting to access a file that cannot be found, either because it has not been previously defined, or because the disk containing the file is not available. For additional information, see Files - Introduction.
Attempting to create a new file with the same name as an existing file. The DIRECT, STRING, INDEXED, SERIAL, PROGRAM, SORT, SAVE, or MKEYED verbs can generate this error.
Defining a disk data file or program where the file name is the same as the name reserved for a system device (for example, PRN or CON) or the disk name.
Attempting to OPEN an I/O device not included in the configuration.
Attempting to OPEN a file with MODE="CISAM" on a system that does not have intrinsic C-ISAM support.
Attempting to access a remote PRO/5 Data Server, but the host could not be located.
Attempting to OPEN files on a Windows NT machine from a Windows 95 machine without the proper permissions.