Unexpected Internal Error (-37100) when adding new expense item from iOS app. Laptop version is fine. Tried delete and redownload app but same problem. How to solve?

Welcome, and thank you for using QuickBooks as your business tool, @asamaya. I appreciate the things you've done to fix the error code you've encountered.

If you're using the QuickBooks Online app, it's no longer supported.

Since you've already deleted and downloaded the app again, I recommend contacting our Support Team. They can help you access these forms. Please also take note of our support hours so we can address your concerns on time.

Here's how:

1. Go to the Help icon.
2. Choose the Search tab and then Contact Us.
3. Enter a brief description of your concern.
4. Press Continue. 

For more ways on how you can reach out to us, refer to this article: How and when can I contact Support? This includes the support hours you’ll want to take note of so we can address your concerns on time.

In case you'd like to track how much you make and spend on each product or service, check out this guide: Add product and service items to QuickBooks Online. This will also walk you through deleting them if necessary.

I've included this reference to help you learn more about recording and deleting business expenses: Enter and manage expenses in QuickBooks Online. This will help you review the transactions entered in the system so we can keep track of your business and profit.

Tap me on the shoulder if you need additional assistance with adding your expense items. I'm right here with my colleague to help you. Take care.