when i open my project after update of Android Builder it shows this error
Try exporting the aia and reimporting it.
I have the same problem, I tried to export sis and it didn’t work.Also, when we try to make an edit on screen1, it is not recorded.
As @Bot said try to export project and reimport. And also try by changing your browser. When blocks not loaded properly it doesn’t save a changes in blocks. One more, copy block to backpack and paste from it (take backup before doing this).
Now try or share your project with us for further testing.