If you want to download a file but QuickBooks not opening the file may be damaged or corrupted. You can repair it using the QuickBooks file doctor tool. First, download the Quickbooks file doctor from Intuit's official website. Install it on our computer and run the setup. Browse the damaged company file and select “check file damage only.”. click on the diagnose file. Enter the admin password to begin the process and wait until it repairs the file.