Interactive Brokers has created a new process for linking your account to third party aggregators such as Personal Capital. Before linking your Interactive Brokers account to your Personal Capital dashboard, log in to your Interactive Brokers account and navigate to Reports > Settings > Third-Party Services. From there click the Activate link for our aggregator, Yodlee. This will create a Token and Query ID for you to use when linking your Interactive Brokers Account.
Once you have your Token and Query ID, search specifically for "Interactive Brokers (US)" at Personal Capital where you can use the newly created Token and Query ID to link your account. This will be used in place of your normal login as it is specific to each third party, so make sure you are using your Token and Query ID to link your account to your Personal Capital dashboard.