Is there a reason why when I send an invoice the app crashes and logs me out?

A corrupted or outdated cache file may be causing the unusual behavior you're experiencing, info2166.

Let's begin by clearing the accumulated app data to start fresh. To clear the cache in your phone's settings, follow these steps: 

For iOS:

1. Go to Settings, then tap General.
2. Tap iPhone Storage, then tap the QuickBooks Online app.
3. Tap Offload App. This will free up the storage without deleting your app's documents and data.

For Android:

1. Go to Menu ☰, then tap More Options ⋮.
2. Tap Settings, then Refresh Data.
3. Tap YES to confirm.

Check this article to see the latest on how to refresh your data in your QuickBooks Online app: See your latest data in the QuickBooks Online app.

If the issue continues to persist, you might consider uninstalling and then reinstalling the app.

In the meantime, you can send your invoice using a web browser through qbo.intuit.com.

I'm also sharing this article that will serve as a gentle reminder to your customers about their upcoming dues: Create and send customer statements in QuickBooks Online.

Please click the Reply button if there's anything else I can assist you with.

It’s a bug on the IOS app.

Instead of clicking the SEND button (which just causes the app to appear to quit), go into the invoice, tap the 3 dots top right and select email. You can then send as normal.

Quickbooks are aware of the bug and it’s in their list to be fixed.

You may also see a popup (also a bug which Quickbooks are aware of) saying:

Invoice needs approval

The changes made to invoice needs an internal approval before it can be sent to the customer

You can ignore this message as the invoice is sent.

See my other post here…

https://quickbooks.intuit.com/learn-support/en-uk/other-questions/my-employees-are-getting-a-message-pop-up-when-trying-to-send/00/1553797