Uncaught InvalidCharacterError" When Connecting to Anaplan

When trying to sign in using certificate authentication in the Anaplan connector, the following error may occur:

An error occurred while communicating with the data source
The web data connector has reported an unrecoverable error and cannot proceed. If the connector has reported details of the error, they are displayed in the pane below.
Error Code: 82BE0673
Uncaught InvalidCharacterError: Failed to execute 'atob' on 'Window': The string to be decoded is not correctly encoded.  stack:Error: Failed to execute 'atob' on 'Window': The string to be decoded is not correctly encoded.
  at Object.base64DecodeUnicode (https://connectors.tableau.com/wdc/2/app/dist/wdc-framework-2.29.latest.js:159:53)
  at Object.getBasicAuthString (https://connectors.tableau.com/anaplan/anaplan/1/app/js/modules/anaplan.helper.js:94:26)
  at Object.ajax (https://connectors.tableau.com/anaplan/anaplan/1/app/js/modules/anaplan.helper.js:361:22)
  at Object.getAuthToken (https://connectors.tableau.com/anaplan/anaplan/1/app/js/modules/anaplan.helper.js:649:21)
  at n.<anonymous> (https://connectors.tableau.com/anaplan/anaplan/1/app/js/modules/anaplan.connector.js:1383:20)
  at HTMLButtonElement.r (https://connectors.tableau.com/wdc/2/app/vendors/lodash/lodash-compat/3.10.1/lodash.min.js:26:189)
  at HTMLUListElement.dispatch (https://connectors.tableau.com/wdc/2/app/vendors/jquery/v1.11.3/jquery.min.js:4:8549)
  at HTMLUListElement.r.handle (https://connectors.tableau.com/wdc/2/app/vendors/jquery/v1.11.3/jquery.min.js:4:5252)