Help me in this error in list view

Please help,
I working to sort data in list view by bubble sort
But this error appeared


Are you using MIT App Inventor ?

I just show method i use but this in koduarl

I think so i knows the solution can i get aia file to solve
or do this I got a runtime error
i have a post on community with same error and it is solved by @Still-learning

1 Like

Thanks so much
This procedure cause this error its to sort data in list view i want to know why ?