Let's tackle this problem and get a better understanding of why your information has been deleted. (Example: Transactions, mileage, invoices, etc.) Don't sweat it. All you need to do is try a few basic troubleshooting steps to help resolve this problem.
Using a private browser or incognito window will allow your QuickBooks to load as a fresh new page to eliminate any errors or glitches within the system. Here's how depending on your session:
Internet Explorer/Firefox: Ctrl + Shift + P
Safari: Command + Shift + N
Google Chrome: Ctrl + Shift + N
If this works, go back to your regular session and clear your browser's history. If this doesn't work, I recommend using a different browser.
These steps should do the trick to help resolve this problem. If you have any other questions or concerns, don't hesitate to contact me. I'll always be around to help. Have a great day!