That error probably means there's an error in the brain script you're using, or in one of the plug-ins.
Suggested fix: Try turning off one of your plug-ins and restarting Hal. If the error's still there, turn off another and restart, until Hal runs without an error. Once the error disappears, the last plug-in you turned off was causing the problem.
Finally, if the error's still there, try going back to the default brain. If that doesn't fix it, either your default brain has been altered, or something weird's going on with your Hal [

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