As a variant try next step or some sources from Net in the following…
https://support.microsoft.com/en-us/help/193952/how-to-troubleshoot-to-resolve-suspected-corruption-in-visual-foxpro
http://fox.wikis.com/wc.dll?Wiki~TableCorruptionRepairTools
https://onlinefilerepair.com/en/dbf-repair-online.html

Copy a valid memo file over the corrupt memo file to access the database again.

NOTE: The original memo field information will be lost unless the valid memo file was an exact backup of the corrupt file. All memo field backup files have an extension of .TBK.

The corrupt memo file will have an .FPT extension, such as OLD.FPT. In the following example, assume NEW.FPT is a valid memo file. To bypass the error message and access the database again, type the following command at the MS- DOS command prompt:

Copy new.fpt old.fpt