I do have this issued from time to time.
But as you all know informatics is NOT an exact science any more!
You make an input to a program and got a result.
If you you make the SAME input to the SAME program you got another result.
That's magic, isn't it?
NO, often the program libraries this program uses are changing and the programmer of that program have not checked this.
The worst thing is an error in a compiler.