Runtime error "java.util.List.iterator() on a null object reference"

[ABG]

Could the 22nd phone be failing because some resource has been exhausted by the 21 other phones before it?

• DHCP addresses on the local router?
• key unique values on the Firebase data model?
• cumulative bandwidth or usage limits?

FAQ Section: Debugging

Introductory Testing techniques, including Do It - MIT Sample Connect -> Companion sequence - @ABG How to Read and Understand a Runtime Error Message - @ABG Common Runtime Errors - @TimAI2 How to Teach Debugging thread - Feb 2025 Advanced Do It' to view procedure results, event arguments and local variables How to run Logcat How to use Do It in a loop Screen1.ErrorOccured message numbers SteveJG monster list of things you should not do How to show raw responseContent from your app wh…