Common reasons for bugs in release version not present in debug mode

Question

What are the typical reasons for bugs and abnormal program behavior that manifest themselves only in release compilation mode but which do not occur when in debug mode?

Answer 1

Without more details, I will assume that "not OK" means that it either does not compile or throws some sort of error at runtime. Check if you have code that relies on the compilation version, either via #if DEBUG statements or via methods marked with the Conditional attribute.