I am not able to alter invoices/estimates, add new invoices/estimates receive payments or get quality help to resolve these issues. (errors 37112)

It's our top priority to provide the best invoicing features in QuickBooks Online (QBO), @skylight specialties. I can share some solutions to fix the behavior you're getting.

Upon checking on our end, we see that the investigation has been closed already. In the meantime, I recommend performing some troubleshooting steps to help us determine if this is a browser-related issue. Too much historical data from the browser causes discrepancies that affect the view and performance of your QuickBooks.

Depending on your browser, you can use either of these keyboard shortcuts to open an incognito window: 

• Google Chrome: Ctrl + Shift + N
• Safari 11 or newer: ⌘ + Shift + N
• Mozilla Firefox: Shift + Ctrl + P
• Microsoft Edge: Ctrl + Shift + N

If it works, you can return to your original browser and clear its cache to start fresh and check your sales tax. You can also use another supported, up-to-date browser to narrow down the results.

On the other hand, you can run through the resources from this article for more hints while working with your invoices in our system: Create invoices in QuickBooks Online.

In the comment section below, let me know if you have follow-up questions while working following the resolutions provided to alter invoices/estimates. I'm more than happy to help you again. Have a good one!