Trying to change a main AA greeting. I have tried from various phones including x100 which is the first digital set on the system. I dial TRAN + 0, as soon as I press 0 I get invalid on the display.
TIA

Without picking up your handset, press 0. Which extension rings? That is your attendant station and the one you need to record the greeting at.

I talked to the designer of the system. He told me the customer wanted to be able to change the greetings from anywhere. He set up a virtual mailbox that could be accessed through the automated attendant. I found his instructions.