i delete a screen so my app doesnot built whats the reason behind this?
I don't know the inner working of the ai2 storage servers, but I know the cure.
Export the aia file of the project.
Rename the aia file to something new.aia
Import the new aia to a new Project name.
If that doesn't help, either upload the aia here for us to examine or post the full build error log, especially the bottom.
I've run into similar issues before, and sometimes deleting a screen leaves behind a broken reference somewhere in the project. I'd double-check your blocks, assets, and any navigation that was pointing to that screen. If the project built fine before, there's a good chance something is still referencing the deleted screen.