Passing ModelBuilder parameter to update cursor gives ERROR 999999?

Question

I have two point layers. I trust the geometry (read: x and y coordinates) from one of them, but not the attributes data. I trust the attribute data but not the geometry from the other one (the attribute tables have different schema). The basic process (shown in a model builder screenshot below) is to spatially join the point layers, join the result to the points with good data/bad geometry and update their shape field with a script. The script produces one of those damnable "999999: Error executing function" errors.

If I manually step through every stop of the process and feed the update cursor a ready-made feature class it works fine, the points move as intended. It's just when it's set up to run in a model that the script throws the error. I have a feeling that I may be passing the parameter incorrectly, but I can't say for sure.

I've tried moving the "fc = GetParameterAsText()" line around (including in the update cursor parameters) to no avail.

I will also point that I shamelessly took the python from a post on Geonet, located here.

The Model: The Script:

import arcpy  
from arcpy import env  

env.workspace = r"C:\Temp\TempGDB.gdb"  

#Get the feature layer from the previous step in the model   
fc = arcpy.GetParameterAsText(0) 

pnt = arcpy.Point()  

#Update the shape field with the new coordinates  
rows = arcpy.UpdateCursor(fc)  
for row in rows:  
    pnt.X = row.X_Coord  
    pnt.Y = row.Y_Coord  
    row.shape = pnt  
    rows.updateRow(row)  

del row, rows  

The Script Tool Properties

Answer 1

It lools like the problem is that pnt has no spatial reference and arc is having a spit, It's that or your field isn't being retrieved correctly, it's best to use row.getValue(field_name) rather than row.field_name as getValue is more flexible. Please ensure the fields X_Coord and Y_Coord exist in your layer (and aren't turned off) in the layer dialog.

Try this:

import arcpy  
from arcpy import env  

env.workspace = r"C:\Temp\TempGDB.gdb"  

#Get the feature layer from the previous step in the model   
fc = arcpy.GetParameterAsText(0) 
desc = arcpy.Describe(fc)
SR = desc.spatialReference # get the spatial reference from the feature class

pnt = arcpy.Point()  

#Update the shape field with the new coordinates  
rows = arcpy.UpdateCursor(fc)  
for row in rows:  
    pnt.X = row.getValue("X_Coord")
    pnt.Y = row.getValue("Y_Coord")
    pGeom = arcpy.PointGeometry(pnt)
    pGeom.spatialReference = SR # apply it to the shape
    row.shape = pGeom  
    rows.updateRow(row)  

del row, rows  

This would definitely work better as an arcpy.da cursor (ArcGIS 10.1+):

import arcpy  
from arcpy import env  

env.workspace = r"C:\Temp\TempGDB.gdb"  

#Get the feature layer from the previous step in the model   
fc = arcpy.GetParameterAsText(0) 

#Update the shape field with the new coordinates
with (arcpy.da.UpdateCursor(fc,["SHAPE@X","SHAPE@Y","X_Coord","Y_Coord"])) as rows:
    for row in rows:
        row[0]=row[2] # X = X_coord
        row[1]=row[3] # Y = Y_coord
        rows.updateRow(row)