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Cannot register debug window class: class already exists

This support note applies to:

  • AO Tax (AU)
  • AE System Release (NZ)
  • AE System Release (AU)
  • AE MAS (NZ)
  • AE MAS (AU)
  • AE Tax (NZ)
  • AE Central Database (NZ)
  • AE Assets (AU)
  • AE Assets (NZ)
  • AE Tax Series 6 & 8 (AU)
  • AE Tax (AU)
Article ID:

In MYOB AE/AO or System Release you may experience the error "Cannot register debug window class: class already exists".

This error can occur if you have tried to open a tax return, a schedule or during a lodgment.

To fix the issue, logout and login back to AE/AO

If you still have the issue restart your computer.

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