I’ve been trying to create new VM , choosing us-central1 and no VM gets created. Message says “A e2-micro VM instance is currently unavailable in the us-central1-a zone. Alternatively, you can try your request again with a different VM hardware configuration or at a later time.”
tried on europe-west4, and us-east1, and same message. I tried standard instance as well. Same message.. Gotta be me., any clue where I can find out the missing / wrong link to debug?
I rolled the dice again and was able to finally build my 3VMs in Vegas location 
It would be great to have a map of what is full and what is available by region - it was a hunt and peck method to finally discover that open location
Good luck
B
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Not sure what to say, but if it brings any peace of mind I had the same issue. Couldn’t spin up any of the e2-* instances within us-central1 region.
It’s hard to believe that those instances (resources) weren’t available on any of these regions and I’d blame a software bug somewhere behind the scene.