Problem with opening new screen with start value useing list picker


i have app and i am using list viewer to select option and open new screen with start value
So, problem is that when test app with usb it open new screen with start value but when i downlode it on my phone and when i choose a option from list it say that unfortunately app is stopped
My App has
5 screen
one is splash screen for 5 sec
second is login screen for first time
3rd is home which has 4 vertical arrangement for each countery which shows on user input in login screen and it have list picker so that thay can change countery from that
4th one has also 4 vertical arrangement for each countery which shows on user input in login
so when i on 3rd screen and chosse list picker option wihch bring me to screen 4 , it not open 4th screen and says that unforcunatly app has been stopped

Please help me

My code for list picker is on image


how to switch screens correctly

The recommended method of switching screens in App Inventor

see also



my block is alright even i test the app with usb on my phone it open new screen after cliking on pist picker option but when i downlode app in phone and choose list picke option list than it says the unfortunatly app has been stoped
and my app has 4 vertical arrengment on one screen, because of i have 6 jpg image on each of the arrengment it not allow me to put more than 4 vartical arrengemant that’s why i am using two screen for 8 arrengment and 4 arrengment on each.

please help me sir


please use a spell checker before posting next time…
as already said, make sure to switch screens correctly, else you will run out of memory
and to find out more about the runtime error, use logcat



Hey @Suresh_Rajpurohit,

Here’s an example of switching arrangements (rather than switching screens:

And here’s a tutorial for working with start values: