This error is a result of the Raiser's Edge Web Server not having enough disk space to operate the Raiser's Edge Web Service successfully. 

To resolve, increase the available disk space on the Raiser's Edge Web Services (REWS) server to resolve this issue.

If your installation of The Raiser's Edge is hosted by Blackbaud: Click Chat with Support and reference this article

If your installation of The Raiser's Edge is hosted by your organization or third-party service provider: please contact your IT department or the service provider directly and advise them to increase the available disk space on the Raiser's Edge Web Services (REWS) server. Note: Blackbaud Support cannot assist in increasing the disc space when the server is not hosted with us.