This error (A connectivity issue was encountered when trying to connect to parcelforce: Server returned an invalid SOAP Fault. Please see InnerException for more details.) typically occurs when special characters are present in the order details, which Parcelforce does not accept. These may include characters such as full stops, commas, apostrophes, and others. It can also include special characters within the order number itself.
To resolve this issue, please follow the steps below:
Click Orders then Overview.
Search for the order.
Click Actions then Details.
Review all fields, including the order number, for any special characters.
Remove or replace any unsupported characters.
Click Save.
Attempt to create the shipment again.
If the issue persists, please raise a new case online and reference the title of this article.