File corrupt and therefore cannot be repaired

Hey friends, something bad here. What, I tell you. I have been using LibreOffice program when I came into my new office. Here nobody uses MS Office. I made some spreadsheets in LibreOffice Calc for our company’s annual financial report. The files were good before yesterday, but they are not opening anymore. Here it is what I get while opening them: “The file myfilename.ods is corrupt and therfore cannot be repaired.” We need those spreadsheets. Is there any way to fix this corruption? Like MS Office does LibreOffice have any inbuilt repair function? Please help me