A question. I want to burn a 1920x1080 25 frame rate to bluray. I have attempted BD to AVC. Multi AVCHD (which wouldn't play in my Sony UBP-X800) and ripbot264. The discs that playback do so at 1080/50. What causes this? The Sony player or is there something I'm missing?
Are you talking about burning to a blu-ray disc? If so, there's no reason to do anything to change the resolution or the format of the original video. However, a 25 fps is PAL. If the region of your player is set to NTSC, you would have to change it to play PAL. You can change it up to 5 times but, the next time you change it it would be permanent. If you want to check it, go here- https://www.dropbox.com/s/5oo902exn1yrntq/Nero11infotool-11.0.00500.exe?dl=0 Download and install the file. Then, run it. You can skip the drive tests. Open the Drive section, select your drive and take a screenshot. Attach the screenshot here. This assumes the drive is attached to your computer. To do a PAL to NTSC conversion, you could use something like this- https://videoconverter.wondershare.com/convert-dvd/convert-pal-to-ntsc.html I use Nero Video but it's not free.
"I want to burn a 1920x1080 25 frame rate to bluray." What format is the source in? Is it on disc or is it in a portable format such as MP4?
I'll trial Nero Video. I'm not attempting to convert from pal to ntsc. It's my Sony 4k Player that's playing it back to 50fps. When I play the file on my laptop, it plays at 24.
According to the specs of your BD player it can play MKV. So is your problem burning the file to a BD disc? The structure of a Blu-Ray format is not dependent on the disc, meaning a Blu-Ray movie can be compressed to fit on a standard DVD recordable, and a BD player will recognize it as a BD disc. If your MKV files is able to fit on a DVD single or dual layer that might be a good place to start. Blu-Ray is a structure more than a physical outcome and if you're playing a portable format off of a disc, then the physical media format probably won't matter. So try burning the file to DVD media as a data file and then let's see if your player can recognize it.
If you're using a trial version of Nero Video, it won't likely burn a MKV. Certain formats such as mp4, etc. which require licensing to use, require a paid version. That said, the "status 3" error is a generic error at the end of the log file for the burn. I would need to see the whole log to determine the real problem. We can do that later, if necessary. Would you mind uploading your .mkv to a cloud service such as dropbox, one drive, wetransfer, etc.; share it; get a link and post the link here?
