I uninstalled an because it had problems sending my invoices. I then reinstalled it again and signed in. But all my previous invoices are not there ?

Hi hobby_2, 

You'll want to log in to your account using a web browser to see if you're able to see your previous invoices. Let me provide you some information and help you retrieve them.

If you're able to access your invoices using the browser, let's reset your app data to refresh your account. Here's how:

1. Click Help on the navigation bar at the top.
2. Select Reset App Data.
3. Allow a moment for the process to complete, and then close the app.
4. Be sure to right-click the app and Run as Administrator when re-opening.

However, if you're still unable to access them using the browser, I suggest reaching out to our support team for other troubleshooting steps that will help fix the issue. They have the tools to pull up your account in a secure environment. 

Here's how to reach them:

1. Sign in to your account.
2. Click Help on the upper right corner.
3. Select Contact Us.
4. Type your concern.
5. Click Let's talk.
6. Select Get a callback.

I have these help articles in case you have other questions about QuickBooks Online (QBO). Account Management.

Let me know if you have any other concerns. I'll always be around to help.