Important Notice

The pages on this site contain documentation for very old MS-DOS software, purely for historical purposes. If you're looking for up-to-date documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.

This error may occur because of one of these situations:
  ■ A statement or command refers to a file with a file
    number or name that is not specified in the OPEN
    statement or is out of the range of file numbers
    specified earlier in the program.
  ■ No ISAM table (or any other file) is currently open with
    the file number used in an ISAM statement or function.
  ■ A file exists with the filename used in an OPEN FOR ISAM
    statement, but it was not created by ISAM.
  ■ You have used an invalid filename in an OPEN FOR ISAM
    statement. A filename must conform to the DOS
    naming convention.
 
ERR code: 52