Hi Kon,
The word "terminates" sounds mysterious indeed so any more details about what you can see would help.
Anyway, I think you can fix your code if you simply replace your line 13 with this:
fieldList = [f.name for f in arcpy.ListFields(fc)]
If you are not familiar with list concatenation (the suggestion above), you can write it using a map function too:
fieldList = map(lambda a: a.name, arcpy.ListFields(fc))
The bottom line is that the arcpy.ListFields function returns a list of Field objects, not list of names of fields in the feature class. To get list of names, you need to loop through the list of field objects and retrieve the name propery.
Hope this helps.
Filip.