Good to see you in the Community, Pezski.
I have some steps that can help you fix the unexpected error message.
You'll get an unusual behavior when your app is not updated, or caches stored are corrupted. Let's make sure to check for the latest update in App Store. Then, open your QuickBooks Online app again.
If you're still getting the error, you can follow the steps below to clear the app's cache. This helps remove the corrupted files cache and fix these kinds of errors.
Here's how:
- From your device's Settings, select Apps (varies by device).
- Tap the QuickBooks Online app from the list
- Select Storage
- Tap Clear Cache.
Once done, open the app again. To learn more about QuickBooks Online app, you can click on this link: Mobile app.
Please keep me posted on how it goes after trying out the steps above. I want to make sure this issue is resolved from your end. Have a good day ahead!