I am following all steps in the video MSFS A310 Tutorial 2: FMC Setup | Real Airline Pilot.  It all worked exactly as shown except right after finishing flight plan entry at 06:32 in the video he clicks on INIT then NEXT PAGE. He gets a page to enter weights, CG, etc.  When clicking INIT then NEXT PAGE I don't get a next page at all, I only get NOT ALLOWED at bottom of the screen and no change to anything else on the screen (still showing flight plan).  So I can't proceed to calculate anything in the performance. 

I tried this several times in FS2020 and FS2024 - same problem occurs.  I have searched Inibuilds and FlightSimulator.com but to no avail.  Any suggestions appreciated. 

In my previous post I meant to say, FMS is still showing the first INIT page 

6 hours ago, DougC said:

NOT ALLOWED

Are your engines running? The INIT B page is only accessible when both engines are off. With the engines running you can only edit some of the info via PROG > FUEL PRED page.

Thanks!