Certified Development Lifecycle and Deployment Designer

Universal Containers (UC) has Salesforce orgs on Unlimited Edition. It currently has four Developer Pro sandboxes that development teams use for different purposes, one Partial Copy sandbox used for training, and one Full sandbox used for user acceptance testing. Another Full sandbox was used for performance testing during the initial launch and is no longer actively used.

Yesterday, a system administrator reported that none of the sandboxes can be refreshed.

What is the most likely action an architect can help the system administrator take?