Cannot edit existing Spaces in a design model which were created in the same AECOsim Building Designer version as the edit.
Use "Upgrade DataGroup Utility" from the Utilities > Building Designer pulldown menu. This will upgrade the DataGroup definitions in the model to the current DataGroup System definitions and catalog that is being currently used in the Dataset. Something in the current DataGroup System was modified since the creation of the existing Spaces so they cannot be edited until they are upgraded to the current DataGroup System Properties.