Solution for changing Big Sur login wallpaper to custom.

One update. I have two Macs, both upgraded from Catalina to Big Sur. The "older" laptop (early 2015 Pro) already had the Desktop Pictures folder with the UUID folder containing the Lockscreen.PNG file. The issue was with the newer laptop (2019 MB Pro) with no Desktop Pictures folder in the Library\Caches folder. Possibly because the older laptop shipped with Mac OS Sierra and was upgraded multiple times along the way while the newer one started with Catalina. Only Apple knows ...

Yes that will change the desktop background. The one I am looting change is when you turn off computer and then turn it back on the background you have when prompted for your user password. That is the horrible background I would like to change. Why is this an issue I just find hilarious. What is Apple doing????

That is only the «default screen after boot» on a Single User system, jamesfromsherman.

On multi-user systems, the «default screen after boot» is different than the individual users’ Lock Screens.

It is this multi-user system «default screen after boot» that I am calling the Login Screen.

It is this Login Screen that is skipped on Single User systems.

Does this help clarify the terminology I’m using?

Do you have better terminology you wish us to use?

Did change all that!

Even put Guest User and FileVault off. The desktop picture in the Desktop pictures (followed by UUID) folder are matching (and access rights on folder are on reading & writing) , but still the lock screen is that ugly wallpaper.

What to do next?

Hi Francois-Stanford,

Yes, it only works for single user accounts and one has to turn off FileVault as well.

Hopefully Apple will address this with a future update. What do you can do is submit feedback at this point and hope they read it. That's all you can do at this point.

Hope this helps.

I have tried this on a late 2013 MBA and 2017 MB, without success. On both MB, the UUID-folder already existed with the lockscreen.png file (pointing to whatever I change the background to).

I changed the permissions, background and restarted, but still have the ugly background on the login screen.

I then deleted the UUID folder, restarted, followed the instructions, but still see the ugly background after restart...

Whoa !

Wait a minute let me clarify this. Here's what interesting. I just tested both lock + log-out user screen.

The screen i want is on the ADMIN account. However...when i log out of the NON-ADMIN [aka Standard User] account i get the rainbow colored background with the option of choosing which of the 3 accounts i want to log in to. aka log in screen.

Please note:

File sharing is disabled [not sure if that matters]

Mac is set to open by default [no password required] onto STANDARD user account.

This only** happens when i try to switch from Standard user to ADMIN account.

Are you saying I need to do these SAME* steps while logged into the standard account ?

Do I need to grant read/write permissions to just the actual photo or the whole entire UID folder it's located in ?

applewarm - I've tried your steps multiple times, and at different times/on different days (just to be sure I wasn't doing the wrong thing repeatedly). I can't get the "start up" or "login" screen to change - match my wallpaper. I'm wondering if using a randomly changing wallpaper is the issue? The "lockscreen.png" file is the correct one - the one I want to replace the Apple Big Sur picture. I have tried to change my wallpaper to a single picture instead of the randomly rotating pictures I typically use without success. Just this evening I again changed my wallpaper to a single picture and still was unsuccessful in having the "start up"/"login" screen change. I did notice this time, that the picture in the folder under Library was the old picture I used when I tried this before - it didn't match the current single wallpaper picture I had set. Also, with my prior attempts I had to copy the picture I wanted to use to the appropriate folder and rename it to "lockscreen.png". Anyone have suggestions? Or agree that my assumption that a rotating wallpaper setting (at some point) has changed another setting and is causing my problem)?

Yes, Zranta, you are getting, exactly, the “correct” behavior for a multi-user system.

Sorry, but none of us have found any better solution for multi-user systems, yet.

Providing Feedback, to Apple, on this macOS, is the best course of action, right now.

(By the way. I suspect that using personal esthetics as a “reason” is, probably, not the best approach. Instead, I recommend an approach involving your desire, as a system administrator, of a multi-user system, to be able to choose a “wallpaper” more fitting to the purpose of your system.)

Can you describe in detail the process to complete step #10 - "Make sure FileVault and Guest user are deactivated", and #11 - "Change desktop wallpaper"? Thank you.

I went through the process as best I could, and the wallpaper changed, but only temporarily before it reverted to the original Apple wallpaper.

pantload wrote:

Hello,

I wish Apple would change this in an up date to Big Sur. Give the user the option of choosing the Lock Screen user background instead of the hideous colorful red blue orange yellow art image. I would much rather it be a landscape image.

Actually, you, the user, will have your Lock Screen set to be directly related to your Desktop Background image—unless something isn’t quite right with your system, for one reason or another.

The Lock Screen is the one you see when you Lock your user account. It is also what you see once you choose a User if your Login Window is set to “List of Users”.

Additionally, if your system is recognized as a Single-User system, and your Login Window is set to “List of Users”, the Login Window (Login Screen) will be skipped, and go straight to the Lock Screen of that single user.

The procedures of this Discussion are to help make sure your system is recognizable as a Single-User system.

Its linked with my desktop wallpaper now. Whatever is my desktop wallpaper the login screen has the same one. I've even tried to delete the Desktop Pictures folder but still same. So I want to have the standard settings.

I’m sorry, charonspacexdragon, but that one image file does seem to be it, though it is possible that some copy is saved somewhere else, and has a different name that none of us have figured out, yet.

There could even be some file containing the information about what image file should be used as the background of the Login Screen, but, again, we simply haven’t figured this out, so far.

That’s why I wrote: «Unfortunately, so far, the only thing we can change is the Lock Screen background for individual users.» (emphasis added)

I never said it is impossible to make a change in the background of the Login Screen. I only stated that we are unable to make this change, so far. The cause may be simply due to our current ignorance.

Hence, at this time, the very best course of action is to provide our Feedback to Apple.

Hint: this is not the place to provide such Feedback.