Can anyone tell me about this error. I can run feature class to feature class conversion in model builder and it works fine. But when I try to add it to a python script I get this ERROR 999999: Error executing function Failed to execute FeatureClassToFeatureClass. I have tried importing the python script from model builder and adding the tool from the tool box it errors both ways.
I found this StackExchange thread - I tested and it works. Can't create Feature classes with the same name, even in different Datasets. I ended up appending my feature classes with an "_<number>" based on the iteration I was working on.
I don't know if this will fix your problem, but I had a similar issue and found that I have forgotten to give the extension of a file name. For example, I have asked the software to save a file with no extension like" .Shp or .Dbf.
