The operation add items to list cannot accept the arguments

[Ramon]

Additionally, some tips on how to correctly switch from one screen to another:

App Inventor Tutorials and Examples: Manager Screen | Pura Vida Apps

Switch screens correctly - 2 methods

Since questions about this have been coming up again and again for years (actually right from the start), here is a short tutorial with a test app. Test it with Companion & with the APK. switchScreensCorrectly.aia (10.0 KB) [image] [grafik] Blocks - Screen1 Blocks - Screen2 There are basically two methods how screens can be switched correctly: Screen1 remains open after switching to another screen. All other screens are closed when you switch to another screen. This means that at most t…

Any good reason because my aia does not open an existing screen?

Try this: TestNestingScreens_revised.aia (15.5 KB) Screen1 remains open to stop it be re-initialised when returning from Main. (Hence the use of tinydb on Screen1 and Main) All other screens are closed when another screen is opened. To test, you will need to compile to an apk for this to work properly.