Strange runtime error!

I have faced a runtime error when I tried to load my application’s home screen.
It shows this runtime error in apk on KitKat:-

> java.lang.stringbuffer.append

And home screen is not initializing on Android 7.0 while it works perfectly in companion.
Here are the blocks:-

adjust your image cannot see the image

I am doing that.
Not working.
Is it bug?