Smart cast to 'Type' is impossible, because 'x' is a mutable property that could have been changed by this time

So I run into this problem quite often lately, most of the time it happens when I have defined a Hibernate Entity in Kotlin, and I wish to use it in my code.

It happens when there's a property that could conceivably be accessed in another thread, cause the two statements, the if-statement and the execution statement to look at different states, and cause a ClassCastException.

The following code demonstrates the message Kotlin provides when writing such a program:

Possible solutions

References

Youtube - Let, Also, Apply, Run, With - Kotlin Scope Functions

https://www.youtube.com/watch?v=Vy-dS2SVoHk