Hi there,
Sorry to hear about this. Looks like the file got corrupt/ damaged. Try moving the pages to a new document (https://helpx.adobe.com/in/indesign/using/pages-spreads-1.html) and see if that helps.
There are multiple factors that can lead to file corruption, however, we can take a look and see if the file can be repaired. If moving pages doesn't help, please email your file to idfile@adobe.com & we will take a look at the file.
I must also inform you that file recovery can't be guaranteed with a 100% success. We'll surely try our best.
Regards,
Srishti