Hi Mani
Running MIKE SHE AD/WQ is only possible in a de-coupled mode, as you know, and therefore, you must defined the setup such that you run WM (Water Movement) initially and thereafter the MIKE SHE WQ-simulation.
Likewise, it is required to setup MIKE 11 in a de-coupled mode and run the AD-simulation in MIKE 11 as a stand-alone simulation (without running the HD-model and AD-model simultanously). Therefore, you must make a AD-simulation which use the HD result-file as an input and this is most likely what is causing your present problem.
Solution should be to make a seperate sim11-file for the de-coupled AD-simulation, where you only activate Advection-Dispersion simulation. In this you must then specify the HD Result file on the Input file page.
Once you have a stand-alone AD-simulation running you should be able to use this in your MIKE SHE setup and run without the present error.