I experienced some troubles upgrading my Manjaro system today. At beginning the error sounds simple, but in deep I had to do some tweakings and packages removes to get everything working again. Anyway let's see first what happened in detail.
linux50-nvidia(could be any other kernel version linuxXX).
Reached this point the best solution was switch to open-source Nouveau driver and run
pacman -Syu again to avoid
nvidia-utils conflict. So I started removing propietary nvidia driver:
pacman -Rs linux50-nvidia nvidia-utils lib32-nvidia-utils
And install the Nouveau driver if you haven't yet:
pacman -S xf86-video-nouveau
Now there isn't any blocked package so you can upgrade your system safely.
Unfortunately after reboot I detected
systemsettings5 or KDE System Settings crashed due a missing OpenGL library. After a little googling I found a post having a similar problem switching from Nvidia to Nouveau, in that moment I realised Nvidia propietary driver was uninstalled, so many OpenGL extensions should be missing. Once done to ensure functionality I removed nouveau driver which is currently causing problems:
pacman -R xf86-video-nouveau.
And finally install propietary Nvidia drivers for your kernel:
pacman -S linux51-nvidia
Reboot and now everything should be working fine.
If you find any problem please report it on Manjaro Forum.