problem with version

hello everybody,

I am new with kodular. when I export the apk. I test it with an old device that has version 4.4.4
but some buttons disappear and items. how I can solve these issues.

Welcome to the community. To me it looks that problem is caused because your design is not responsive so depending the phone’s screen you may not see some elements. Set sizing to responsive form project properties, try to work with persentages in width and height instead of pixels.