Hi,
Create a new blank CDX and overwrite the corrupted index and then reindex.

As for the cause of the error, it could be many things, more info required.

>Hello all:
>
>Sometimes, (last time it happened when trying to build a view) I suddenly got an error message saying "Fatal error... line ####..."
>The program then crashes and my indexes are destroyed. Anyone has a clue as why this happens, that is so severe as to destroy my indexes?
>Is it safe to copy the indexes from a backup file and paste them on my actual development application?
>Thank you in advance...