Not enough space in your data segment to allocate a new data segment.

Make sure the Read-Only attribute is not selected on the data file (.4dd, or .data on Mac) or program file (.4dc). This can happen if a CD-RW is used to copy Freezerworks from one machine to another. The Read-Only attribute is set by the CD copy software when the files are placed on the CD-RW, and are retained by Windows when the file is copied back to the computer.
Are you connecting to the correct data file? If you have two distinct copies of Freezerworks installed, sometimes both copies are connected to the same data file. Freezerworks will prevent data being saved by the second copy to ensure data integrity.
Make sure there is enough RAM available to run Freezerworks (see System Requirements for specific version information).
If you are running a Log File (4D Backup) and the volume on which the Log File lives is full, this error may occur. If you store the Data File and Log File on separate volumes (good practice), there may be plenty of room to save the record in the Data File, but not enough space to add to the Log File.
Reboot the computer running the Freezerworks program. This will reset the memory allocation table.