It's not the submission that fails: The error message indicates a problem in line 2 of your script. Submitting a signed form definitely works. Are both fields still accessible? I would add something like this for debugging purposes:
app.alert(this.getField("CustomerName").value);
app.alert(this.getField("ChangeType").value);
Hopefully this will tell you which field is causing the problems.
Karl Heinz Kremer
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