Today MYOB confirmation servers stopped responding. This has resulted in MYOB software being able to write data as the inability to confirm the data files results in read only access.
https://status.myob.com/ reports

Identified, 2019-04-29 10:30:03 AESTWe are still working through the incident. Be assured we are treating this with the highest priority and have multiple internal and external parties working through it. 

We are seeing services restored intermittently at times before stopping. We’re confident we will get the issue resolved soon, but no current ETA