and maybe i must say this i m Turkish in the my project the language is turkish
The Screens soru_b, soru_c, soru_e and tikla could be one single screen with the components hidden/displayed as required. However, this is just inadvisable coding, not a fault.
ok thanks, but i want to present the project without changing it much, what can i do, or can you throw me the apk
You need a bit more patience Oyan.
ok thank you very much what do you suggest me to do now
OK, Screen management fault. Does not cause the build problem you have but will cause the App to crash when installed.
You cannot do this:
Screen1 already exists - you are opening another Screen1. Instead, do this:
This issue is on more than one screen, so fix all of them.
I tested this but it doesn't matter
If I tell you it matters - then it matters. Shall I continue to help?
but where will it open when the screen turns off
I do not understand your question. Let's just get the fixes done - OK?
if i do this block
which screen coming
It will be the Screen that opened it.
Do you have a chance to fix and give me all the mistakes because I am not very professional in app inventor
We are not here to do your homework for you Oyan.
i m starting this 2 month ago ),,,,:
i do all 
this in all screens bu again give dx stage error
Similar here. Screen tikla was opened by Screen oyna - so to return to oyna, just close tikla.
Fixing bugs is a good way to become better at programming.
It's going to be helpful if you pay attention to my notes. The bugs found so far would not prevent the Build, but they would crash the App once installed.
and in here
i must close this screen and give a value the other screen ,how can i repair this