Solved
Same object has different identities, so "the target object does not exist" error occurs.
Hi, I use property checkpoint on an alert. I get the target object does not exist error. Because the parent object was not found. When I check parent object's identities, with object Spy, I realize...
I guess I have found a way. I have changed the location of the object in name mapping and aliases section. I transport the object from problematic parent to reliable parent. When I run the test, it passes.
But I still don't understand why alert window's identities changed project to project.
