Excel Found Unreadable Content in My name.xls

Dear Professionals,

I have an excel file with .xls as extension, and access the same through Excel 2010.

Till Last Friday was working fine, and suddenly when tried to open on Monday, encountered this problem.

I sit in India and access this file saved in US through Filezilla.

This excel has almost 8 different sheets with data.

Request all of you to please provide a solution for this.

This is the only copy in the US and we do not have a backup for the same.

Please hemp me out.

Thanks & Regards
Kamal