After updating GRUB starts on emergency mode

[Mirdarthos]

This might help:

[HowTo] Resolve an unbootable Manjaro (black screen, login failed, cant boot, etc)

When we have problems gaining access to our systems it is difficult to gather information, let alone fix any problems. Here we will cover common causes and solutions to ‘manjaro wont boot’. TTY If your desktop does not load properly then you might still be able to use most, if not all, functionality by dropping to a non-graphical TTY. By default your system will have multiple TTYs, with each corresponding to an Fx key. Your desktop is assigned to one as well - most often F1. You can change…

or perhaps even this:

[HowTo] Recovering from an interrupted update/upgrade

Difficulty: ★★☆☆☆ So you couldn’t wait until the update process had completed and you went for the reset/power button, didn’t you? And now you’re getting the message that you don’t have a kernel installed. Well, you’re not the only one — we’re seeing it happen all the time. So, here’s how to fix it, you impatient n00b. If you don’t happen to have a recent Manjaro installer USB/DVD/CD handy, direct your browser to this wonderful page, download t…