Can you please run the process in debug mode in your van and check what activity it’s is failing at?
Looks like exception is happening in initialisation state and then control is moving to end process state right away and trying to send email.
This null exception can occur if exception happened even before config could initialize in which case if you are trying to use config value in sendexceptionemail, it will throw this error
Also confirm when you have set up the dev instance for your vm, all the assets for that are supplied value.
Regards
Sonali