What codec are you using for render ?
I'm not very tech savvy, but in project settings it shows that I use 'Mercury GPU Acceleration (OpenCL)', though I have switched it to 'Mercury Software Only' and no changes show.
Is that what you're asking?
No I wasn't talking about that.
" It's only when rendering in the Render Queue that everything–the transitions, movements, and videos– gets moved one frame backward" So your issue only appears once you have exported a video out of your composition ?
sorry and, yeah, it's only once i've exported the video
How do you know it's one frame off? Unless you fouled up the frame rates and forced AE to render something using custom settings it's highly unlikely that the frame rates are different and there are timing errors.
Do you know how to read the timeline in AE or a NLE? If you create a comp that's 1 second long and 24 fps then move the CTI to the last frame the display will read 0:00:00:23. This is normal because you still see an image and the last frame has yet to play. If the CTI was at the start of frame 24 then one second would have passed and there would be no image in the composition panel because the video would be over.
To check your render against your original comp drop it into AE, make a new comp from the rendered footage by selecting it in the Project Panel and creating a new comp from selection. Now drag your original composition in the new test comp and put it on top of the render. Using the Modes column (press F4 to reveal it if it is not visible) set the blend mode of the top layer, your original comp, to Difference. The frame should be black except for some possible compression artifacts showing up. Step through the comp and look for timing errors.
If there are timing errors then you were probably working in a 29.97 fps comp, had the timecode display set to NON DROP FRAME and you simply don't understand the difference between drop frame and non-drop frame timecode. Non drop frame timecode display does not display the correct time and frame number, it does not drop frames, it just counts every frame making the time + frames and the hours, minutes and seconds display slightly off. The longer the video the farther off the time display is. You should always be using drop-frame timecode if you are working with NTSC footage at 23.976, 29.97 or 59.94 fps.
If none of those suggestions help we need to see screenshots of your AE project with the problem comp selected in the project panel so we can see the composition settings, the CTI set to the first frame where you see the timing error, and another shot of the AE UI with the rendered footage selected in the Project Panel, the footage panel visible and the CTI set to the same frame number where you see the error.
I'm guessing that you either have fouled up frame rates or don't know how to properly read the time display in AE or a NLE.
Actually there is a H264 decoding bug that eats the first ot two first frames of the video. It depends on the H264 generated... I think AE Quicktime and AME generated H264 don't have this issue anyway
I know that it is one frame off because I've been editing this closely and the transitions are moved backwards as is the video.
I am mostly working with clips that are 30 fps and changing the composition to match that actually worked. This only makes me realize how much more practice I need with AE and how rushed this project is.
Thank you, Sir!