When attempting to log in to ArcGIS Pro with an ArcGIS Online organizational account, the following error is returned:
Error: Unable to establish connection to https://<organizationURL>.maps.arcgis.com
Depending on the cause, perform any of the listed workarounds below.
Change the organization URL in ArcGIS Pro
When launching ArcGIS Pro, ensure the correct organization URL is used in the sign-in dialog box.
Alternatively, if ArcGIS Pro is currently running, perform the following steps:
Update Internet Explorer
For systems running ArcGIS Pro 2.5 and below, update to Internet Explorer 11. For more information on updating Internet Explorer, refer to Microsoft: Run the latest version of Internet Explorer 11.
Add ArcGIS Online sites to the organization's allow list
Add the following sites to the allow list:
Note: This action may require the assistance of the organization's IT department.
https://*.arcgis.com https://*.arcgisonline.com https://ago-item-storage.s3.amazonaws.com https://*.blob.core.windows.net
Add ArcGIS Pro to the allow list in the Group Policy (GPO) settings
Group Policy settings may prevent ArcGIS Pro from running smoothly. Ensure ArcGIS Pro is added to the allow list in the Group Policy and firewall settings. This is done by the organization's IT department.