Hi Jason Thomas,
Welcome to the Microsoft Q&A Platform! Thank you for asking your question here.
There is an internal issue with the deployment process and during the disk creation process. Please try below troubleshooting steps:
If you’re trying with an ARM template or CLI commands, check that the parameters for disk creation such as disk name, SKU, and configuration settings are correct.
Check if your subscription has reached its Quota limit for managed disks.
Once retry the deployment, there might be transient issues with Azure portal.
Please look for specific error messages or codes that can provide more context.
If you have any further queries, please do let us know. If the information is helpful, please Upvote it and Accept Answer for the benefit of the community.