Model Builder Generate Tessellation "spatial reference does not exist"

[LamkinKatherine]

Hello all. I am looking for someone to help me out with a recurring issue I am having when using the 'generate tessellation' tool in arcgis' model builder. I am working with a shape file that is in a projected coordinate system that I am not able to generate a tessellation on. Every time I try to generate one, I get this error message: 

This is the tool that I am using. A projected shape file is connecting to the create spatial reference tool and is also connecting to the red generate tessellation bubble. When I do not use the "create spatial reference tool", I get the same error message.

@DuncanHornby Do you or other have thoughts ?

Thank you.

[DuncanHornby]

I would not use that tool, that's for creating a spatial reference which you would then assign to a dataset. If the tessellation tool is complaining about a lack of a coordinate system it would strongly suggest to me that your input dataset does not have a coordinate system. You don't say what the input layer is, how it was created and although you claim to say it is projected you never state what it is!  If you go to the properties  of the layer (from contents panel) and look under sources what does the spatial reference say? If it says unknown then the dataset is missing specific information and that's something that can happen with shapefiles (which by the way are a very old data format, use file geodatabase). If you know for a fact that it should be in coordinates XYZ then you can use the Define Projection tool to set it.