The app only generates 1 QR code for the day. This happens when you mark the first train on a new travel day. After that you add extra trains on that day to your trip and then mark them for travel. That adds the journey to the pass.

No extra qr code is generated , just use the same one for that day and show the days listing with the train she is on at the time.

Thanks, but she’s not using more than one train a day. She’s just leaving Vienna and can’t see the QR code for the train to Budapest. Her friends she’s travelling with aren’t having this issue.

Have I misunderstood?

If she is following the process of adding the train to her trip and then marking it for travel it should create a travel day with the journey showing . She then should see a button marked show ticket and QR code appears. 

There will be others who may offer more ideas.

It is quite difficult to troubleshoot this without direct contact to the person with the problem. But here goes:

1. What is your app version? See More, scroll to the bottom. If it is lower than 25.0.0, then update.
2. Turn off battery saving, data saving, airplane mode.
3. Check the basics to run the app:
   https://eurail.zendesk.com/hc/en-001/articles/5545614121757-Basics-to-run-the-app
4. Delete the app's cache and the stored app data and try again.
5. Restart your app and try again.
6. Restart your phone and try again.
7. Do you have an iPhone or Android? Which version of the operating system?
8. If nothing helps, go to More > Settings, scroll to the bottom and enable error logging. That won't solve the problem but will help customer service.
9. Create a support request:
   https://eurail.zendesk.com/hc/en-001/requests/new
   Give them all details, screenshot(s) and mention when you will start to travel. It doesn't help to say it's urgent, they need a date, so they can properly prioritize.
10. Also send your device ID to customer service:
    https://eurail.zendesk.com/hc/en-001/articles/4571649483165-Contacting-us-about-an-issue-

Additionally, if the app is not working correctly, then the extra costs can be claimed back from customer service.

Absolutely unacceptable app. Seriously, we should have just bought point to point tickets. Not to be able to access the QR code, which is the MOST BASIC FUNCTION is absurd.  What a sad joke, and of course, no “official” help, no “instructions to display the QR code” under the help section, really ?

Blame the customer… bad phone, not latest version, etc.

This is an overview of how to use mobile pass https://www.interrail.eu/en/interrail-passes/interrail-mobile-pass/getting-started

While I don’t think it is as easy or reliable as it should be it is not impossible to use either, most people do manage to use it properly so if you are having problems then ask for help.

Tell your daughter to switch the phone to flight mode and see if the app works better. The app can behave strangely if the internet connection is unstable.