Dear Doug1,
It seems strange that the file was corrupted by being too big as I believe the Limit on Data in a CardField is 256 spaces or characters per field (See Help|Index and then maximum) and 100 fields per card and 90,000 Cards per Cardfile (though I myself have never.. surprisingly tried that amount!
FIRST, using Windows Explorer make a backup copy of the original preferably some other place than on the Computer you are using.
Have you tried scanning the Disc that the File is on to try to repair any damage, or if that fails, to at least recover some of the Data you could try
1. Creating a new Cardfile that has the same fields.
DO NOT COPY the original, create it from scratch.
2. Then move all the Cards from the damaged one to the newly created one (Save the empty new one under a different name first).
HTH
If not post again with more details of Operating System, Sidekick version, and number of Cards/Fields.
Regards Jim
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