Any troubleshooting tips/documentation for when this happens?
⚠Do not edit this section. It is required for docs.microsoft.com ➟ GitHub issue linking.
Thanks for your question. It looks like you're working through an issue with your scenario or implementation, rather than an issue with the documentation. Here are a couple of options where you might consider asking your question:
I think it's an issue with the documentation if I follow the documentation strictly and no agents are shown in the agent pool I created. (I see a few people have also reported the same issue here)
The az cli code you have on this page for creating the VMSS (#4) also breaks at:
--load-balancer ""
with az cli saying that it is an invalid parameter value or "expected one argument":
az : ERROR: az vmss create: error: argument --load-balancer/--lb: expected one argument
Had the same problem.
I was trying to create the vmss using powershell on a mac (for Windows vmss). I noticed this comment in the docs:

It seems this is required for every type of az cli command, not just Windows. When i used the single quotes as recommended, the command got to the password stage.
@norman-v, @ossentoo -- thank you for clarifying.
@steved0x -- please look into this issue.