There was an error when attempting to accept the invitation response

Error Message

When attempting to import an invitation response for a Portal for ArcGIS and ArcGIS Online distributed collaboration, the following error message is returned:

Error:
There was an error when attempting to accept the invitation response.

Cause

An incorrect guest organization URL address is specified in the invitation link to generate the distributed collaboration invitation file. This may include an incorrect web adaptor name in the URL address.

Below are examples of incorrect and correct URL addresses.

Incorrect URL:

https://<machine_name>:<port_number>.domain.com/arcgis/home

Correct URL:

https://<machine_name>.domain.com/webadaptorname

Solution or Workaround

Remove and reinvite the guest organization

Remove and reinvite the guest organization using the correct URL.

Note: 
If deleting and reinviting the guest organization fails, contact Esri Support to delete the old invitation URL logged to the gw_participant_info table in the ArcGIS Online database.

Create a new distributed collaboration

1. Log in to an ArcGIS Online account with administrative privileges.
2. Delete the existing distributed collaboration. Refer to ArcGIS Online: Delete a collaboration for more information.
3. Create a new distributed collaboration. Refer to ArcGIS Online: Create a distributed collaboration for instructions.

Note: 
When inviting a guest to the collaboration, ensure the correct URL address format as specified in the Guest Organization URL is entered in the box for the invitation.