Vault freezes and crashes for an unknown reason

Hello experts
This is the first time I am attempting to utilize Vault for copy design functionality.
All of my folder paths reprocess/copy, and the suffix seems fine. But after clicking ok the whole process freezes and I am getting the following error message (please see the below attachment). I need to solve it.
Please help.
Thanks.

Error:
The underlying connection was closed: An unexpected error occurred on a receive.
