To summarize below so you don't have to read the whole thing. I had issues too with the premium edition and I use FSUIPC, but I am able to use the aircraft.
1. Initial load, it took a long time from when I hit fly to when the sim loaded. This only happened the first time. I loads fast now (could be like how MSFS2020 had long load times when you first used a new aircraft
2. First time I loaded the aircraft into the sim, the controls were dead. I couldn't even turn on the batteries. I couldn't even get my throttles to show up in the Throttle calibration. After restarting the sim, everything works and continues to work on repeated tests.
3. Hitting ESC and selecting RELOAD causes the sim to immediately stop responding. Selecting MENU works perfect. This still continues to be a small problem
4. I am using the latest update for the MSFS2024 (the update from 12/11/2024), the A300 (I just purchased and installed it today from INIbuilds 12/11/2024), and FUSIPC (7.5.0)
So I too had the problem with A300 Premium pretty much being dead in the water. When I clicked to start the flight, it did take a REALLY long time for the sim to load up. It sat playing the loading animation with the circle in the lower right spinning. I thought the sim was frozen, but if I hit ESC, it brought me back to the free flight menu. I use FSUIPC to set my controls (Now that I am getting to know how to use the build in control system, and that it can be set to each specific aircraft, I am probably going to stop) and it is required for the ACARS for my VA. When it did finally load, I tried setting control bindings through FSUIPC and nothing was responding. When I went into the Throttle calibration menu on the EFB, it showed now input. Then when I clicked on buttons, the sim did nothing. I couldn't even open the cockpit door. I could move the camera around and go in and out of the aircraft, so the sim was not frozen. I then hit ESC and hit the Reload button. This caused the sim to crash. I restarted the simulator and now everything seems to be working fine. I was even able to calibrate some controls through FSUIPC and it seems to be working. I then hit reload and it immediately froze the sim. Subsequent trials seems to show that reloading the flight causes the sim to freeze. It goes back to menu just fine.
