I have created a model with the goal to define the projection (XY & Z) of multiple .flt files within a single folder. The model and the single Define Projection Tool works if only trying to define the XY Coordinate Systen (CS), but not both XY & Z. After the model runs through, the projection stays unknown when I define both the XY & Z Coordinate System. I compared the .prj files, and when I remove the information about compound coordinate system (COMPD_CS), the projection is defined both XY & Z. Please see attachments. Does anyone know why this is happening and if there is a work around?