For one section of a model in ModelBuilder 9.3, the tool doesn't recognise that there is a precondition. I have saved, shut down and restarted, and refreshed the link between the input data and the tool as well as refreshed the precondition link with no luck. The tool is supposed to calculate fields in a feature class (an output from earlier in the model) but it doesn't pick up that the fields were added in the previous step (precondition step).

Here is a picture: http://www.tiikoni.com/tis/view/?id=a72e160


1 Answer 1


sometimes you may need to run the model up to that point so you can continue to build it. eg it may only recognize the new fields once the model has been part run. also if you are having problems with one particular tool i would advise to delete that tool and drag in a fresh copy from the toolbox.

  • Thank you for the responses! I have run the model up to that point several times and the feature class definitely contains the added fields but no luck. I will try adding in fresh tools as these were a copy and paste. Thanks again.
    – ams
    Commented Dec 17, 2013 at 15:01
  • Just to report that when I rebuilt the model with new tools rather than cutting and pasting, there were no more precondition problems. Thank you.
    – ams
    Commented Dec 20, 2013 at 14:21

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