Hi Dbminter, thanks for your tips!
I'm attaching two pictures, one of the writer and other of the discs. I bought both on Amazon, and I precisely choose Verbatim thinking it was a quality brand. As you can see on the picture, it only names Verbatim and on the back the warranty refers to www.verbatim.com . What brand do you recommend me? Is there a way to discern CMC discs from true Verbatim ones? Do you think that once written these discs can be trusted for keeping the data safely for a long time?
Today I could finally burn a bluray. The hint about the USB port gave me an idea, my writer does have 2 plugs, one for the data that it's a 3.0 and a 2.0 for extra voltage. I had the 3.0 pluged in the right place, but when you said that, I wondered if having the other port connected was necessary and if it could be interferring, so I unplugged it and only used the 3.0
I also set the speed to 6x as it says on the discs instead of letting the program to adjust it just in case, and instead of writing the files directly on the disc, I created an image of the files and then used the "write image file to disc", and it did the trick.
Thanks for your help, have a great day!