This warning indicates that the initialization order defined by the Delphi language, that specified by the order of units in the uses clause, is not guaranteed. 

The RunClassConstructor function is used to execute the initialization sections of units used by the current unit in the order specified by the current unit's uses clauses. This warning will be issued if the compiler cannot find this function in the .NET Framework you are linking against. For example, it will occur when linking against the .NET Compact Framework, which does not implement RunClassConstructor.