For 8 years i have been happy user of Endeavouros. I would never ever thought about returning to Windows. Never even in my darkest thoughts. However in last month my both computers were unable to boot due to Failed to mount Efi error. Yes, i was forced to reinstall them. I have never in past 8 years experienced situation, that after every single update, i got this error.
I even installed LTS and ZEN kernels on my working laptop, which i am using for my work and where reliability is everything, in thinking if one kernel became bugged, i have backup booting solutions. But no. Today, after installing update, all 3 kernels gave me same Efi error.
Before some clever person with thorought knowledge of Linux write me something, i want to say i am one of those mainstream people that is not skillfull enough for Chrooting etc. If you guys want to have people quit Windows and go for Linux, how is it even possible, that such a critical and fundamental act, as booting into actual OS, is such a fragile ? I have never experinced this on Windows. I have been using AntiX on my old laptop for 2 years and never had this problem. So with all due to respect, i ask, what the heck is going on these days ? I dont have time to learn chroot etc guys, i am person, that is happy when sucefully install stuff through Yay. I have alread lost lot of money and time due this situation in last month. Not talking about stress, when your working pc is unbootable. Absolute helplessness…
First thing I would do is systemctl status efi.mount to check what happened with the efi partition.
Also, for your understanding, EndeavourOS isn’t a distro that beginners should use as their first distro, because of its Arch Linux base and rolling release. In my opinion, it’s more like a next step for people that want to try more DIY systems without going directly to Arch.
But probably, you’ll need to chroot anyways (but it’s not that hard). If you do not really want to have to deal with very periodic issues (which you’ll find in EndeavourOS, you probably shouldn’t use an Arch-based)
Nothing special. I got new laptop. So i installed Xfce EndeavourOS on it. Since first update, i started to get this Efi error, which i dealt with by reinstalling system. I thought my solution is to have multiple kernels. I was wrong.
I have also home desktop, on KDE Plasma, which had same iasue 2 weeks ago. For installation i am usung Liveusb online method. Never had these problems…
I cannot assist you more, sorry, because I’m not a pro. Wait for someone else to help you.
And yes probably you’ll need to chroot, but wait for someone else to reply.
I personally don’t care what YOU use. I believe in using tools that are needed to get the job done. Also should note since EndeavourOS is based on Arch it is designed for the PROFICIENT LINUX USER.
May I suggest that if your not going to learn how to manage the TOOLS you choose then to choose a different tool. Fedora may be more your speed.
Once you have successfully chrooted in to the system you should make sure your internet works and try to update again. If the update doesn’t fix it you could then try to reinstall the bootloader.
Probably reinstall-kernels didn’t work properly because /efi isn’t mounted, so chroot would be helpful.
Another thing, unless you want to learn more about this distro and go through problems you will evetually find. I would probably use another distro.
Fedora is my recommendation, and I install it on all the computers that aren’t mine, it’s a good distro that updates almost as fast as endeavour and you have to deal with less problems. If you find yourself switching to Fedora and have problems, I can help you.
Have to chroot now 
right ?