All my data has disappeared from my quick books. Error 4002

I want to ensure you're able to fix the error and recover your data, Info. 

Error 4002 occurs when the Adaptive Server rejects the login request. To further review and help fix it, I recommend reaching out to our Product Developer. To do so, you can post your question on our Intuit Developer forum. Here's how:

1. Go to the Intuit Developer page and select Sign In.
2. Log in using your Intuit credentials (select Sign Up if you don't have an account yet).
3. Next, scroll down and click the Contact us option under Intuit.
4. In the What do you need help with? page, choose QuickBooks Online.
5. Click the Ask a Question button.
6. Then, enter the details of your concern.

For reference about the error you receive, feel free to read this link: Review QuickBooks Online Accounting API error codes.

Once everything is fine, here's a helpful resource that you can use as a guide in making sure your transactions are allocated to the correct accounts: Categorize online bank transactions in QuickBooks Online.

Don't hesitate to leave a comment below if you have other concerns managing your account. I'm always here ready to lend a hand. Have a good one.