Think I figured out what's going on.
Via TWRP it says the files were corrupted, although the file sizes were identical.
I MD5 checked the files in my computer and they're ok, but when checked already inside my phone or SD they're not.
Instead of copying the files via USB cable I removed the SD card and inserted directly in my laptop slot and copyed the files. MD5 checked and they're ok...
After I tryed again copy via USB and the files were corrupted again.
I think my desktop USB or maybe the Samsung drivers are doing that.
Well, problem solved. I hope this helps other people in future problems.
Thank you all for your help and support. Keep on with the great work.