Unable to add load options

qk4-li3

I get this message in red when booting up: "Unable to add load options (i.e. kernel command) line measurement to PCR 12: Volume Full"
What is it and how do I (try) fix it?
(Computer does boot/start to Solus, regardless)

About: Vivobook 14_ASUS Laptop E406SA, Budgie 10.9.3, Solus 4.7 Endurance, 64bit, X11, Linux 6.16.12-323.current.

Backround Info: This is my Sweetheart's laptop. I installed Solus for her long time ago. I noticed (using CLI eopkg), that kernel update failed. I think it wasn't the first time, because (in closer inspection) kernel version was strangely low, despite me keeping this machine up to date, usually with (now EOL) Software Center. There was Windows 10 "residue" @disk until this day, so I had to make space (with gparted). EFI partition showed only 260MB size (!!!). EFI is now 954 MiB.
Also, my first time using efibootmgr and trying to remove excess boot entries. There's still one called something-microsoft which I was not able remove. But there's enough space now at EFI partition.
I'm more familiar with BIOS. This EFI thing sucks Bill Gates' Crown Jewels.

BuzzPCSOS

qk4-li3 This answer is based on my own personal opinions. Take from it what you will.

Although Solus is a rolling distro a lot has changed including the required size of the EFI partition. A clean install from scratch might sort out a lot of your problems. Use the latest Solus iso.
If you only need to run Solus it can be helpful to carry out a full wipe of the hard drive partition table (to get rid of any stubborn Windows bits) using a partition tool like GParted or similar. Backup anything needed first, everything gets deleted.
Some users are having issues with the latest updates on Budgie. It might be a good idea to wait until the Solus team has devised a satisfactory resolution.
The Solus 4.8 Epoch ISOs will be released soon (sorry no completion date given) which would be a good choice to use for a fresh install as that will limit the amount of updates that are required and many bug fixes will come tested and already baked in.
Note on UEFI booting. This is the modern replacement to BIOS boot and has it's own strengths and weaknesses. Booting to multiple OSs is harder using UEFI. Generally it offers a faster, more reliable access to your OS than BIOS.

Use the Solus Install Guide.
Edit: Added a few bits that I missed.

qk4-li3

BuzzPCSOS Well, lots of good points and things to consider...
edit: Still curious about that message, though.

BuzzPCSOS

qk4-li3 Solus doesn't always live well with Windows, experience varies.
A full wipe (erase partition table) and then let the Solus installer call the shots seems to be the most trouble free way to get your OS up and running.
Usually.
Experiences no doubt vary but it has always served me well on UEFI installs.