Thank you for your post.
When users enter new records, the information is written directly to the database file. There are a few reasons why a record isn't saved. The most common being the user actually enters data in Find Mode, which will never save a record.
Infrequently, a file may become damaged. Usually in this case, no records can be added after a certain point, so this may not apply to you. However, use the Recover command under the File menu to recover the file. When finished, open the recovered file and see if there is any trouble adding and saving records. If all looks well, then remove the old file and rename the recovered file back to the original file name.