What does the error " CheckAndSetConstructionProperties" mean? How can it be fixed?

I am running a simulation on openstudio and I get the following 2 errors:

* Severe * CheckAndSetConstructionProperties: Inside Layer is Air for construction Wall 1 * ~~~ * Error in material F04 WALL AIR SPACE RESISTANCE 2

* Severe * CheckAndSetConstructionProperties: Outside Layer is Air for construction Wall 1 REVERSED * ~~~ * Error in material F04 WALL AIR SPACE RESISTANCE 2

What does this error mean and how can I fix it?

Thanks

It looks like you are placing the material layer F04 Wall Air Space Resistance at the inside surface of your wall construction assembly named Wall 1 and at the outside surface of the list of your wall construction assembly named Wall 1 REVERSED. This material layer represents an air gap for adding insulation to wall assemblies. EnergyPlus only allows for air gaps to be placed between opaque material layers.

You can fix the error by adding an opaque layer at the end of the list of layers in the construction Wall 1 and at the beginning of the list of layers in the construction Wall 1 REVERSED.