Dataload Error on Account

Hi all,

Does anyone know what this error means? I'm updating the Account Owner via a Dataloader.

The new Account Owner User does have a valid email address and is Active

AccountTrigger: execution of BeforeUpdate
caused by: System.EmailException: SendEmail failed. First exception on row 0; first error: INVALID_EMAIL_ADDRESS, Email address is invalid: null: [toAddresses, null]
Class.AccountTriggerManager.processOwnerChange: line 31, column 1
Class.AccountTriggerHandler.handleBeforeUpdate: line 4, column 1
Trigger.AccountTrigger: line 4, column 1

Thanks!

#Dataloader #Account #Apex