I'm really stumped. I'm getting the below error when trying to refresh my data pulling from Project Online. It's always coped fine with null values before and I can't see why it's suddenly failing. I'm starting to think there is an issue with the code so have put this below as well. Any help greatly appreciated as I'm totally out of ideas!
You may try to replace these null value to a default value before your operation.Below is the similar post for your reference.