You can not load the data without having loaded the header, hence it can be assumed that ReadHeader(IDiagnostics) has already been called.
public virtual void ReadData(
IDiagnostics diagnostics
)[Missing <param name="diagnostics"/> documentation for "M:DHI.Mike1D.ResultDataAccess.M11FfBridgeBase.ReadData(DHI.Mike1D.Generic.IDiagnostics)"]