We apologize for the inconvenience caused.
From your question we understand that you are getting an error while trying to create a virtual machine. We tried multiple times to create the virtual machine using the same configuration as shown in your screenshot. We were able to create the virtual machine.
Could you please re-activate the sandbox and retry and let us know how it goes.
I understand you are following documentation, just to isolate the issue can please try selecting a different size of SKU and retry.
Can you please provide us with screenshots which include all the settings on the basics tab.
We will be more than happy to follow up further.