This issue has been resolved.
From the 31st of August 2021 some projects have been experiencing launch failures in the 'tasmania' availability zone.
tasmania-s and tasmania-02 are currently unaffected and projects with access to those zones are able to launch there instead.
Investigations are ongoing in to the root cause.
11:15 Update; The cause has been identified and work is underway to rectify the problem
11:43 Update; Successful launches have been confirmed in the tasmania availability zone.
We recommend affected users contact the helpdesk if they require assistance in this matter.