I deleted all the default materials from C:\ProgramData\SketchUp\SketchUp 2021\SketchUp\Materials as I don’t use them.
And the next time I fired up SU the Installer ‘fixed’ my installation by recreating them!!!
Is there no way to have them gone and keep them so?
I don’ think there is. I don’t know what would happen if you set the Materials folder to be read-only after emptying it.
I would perhaps import all the materials I frequently use and store them in my template. Then I would almost never need to have other tab than In Model open in my materials browser.
I just replicated your steps…
I can delete / rename the default Materials folder at the path you showed and SketchUp v2021 does not repopulate the materials in the subfolders as it restarts, although when it restarts it does make the now missing Materials folder - which is then empty…
If you run the installer exe again and do a repair it will fix the missing Materials from the backed-up msi ?
But for me it is possible to at least remove the default materials until a major change is made…
Try double-clicking on an existing SU file to open SU, that’s when I was getting the installer. (It also remade the SU/Layout/Style Builder icons on the desktop)
If I open SU from the app icon (blank file) it was fine (ie the mats remained gone)
I can open a SKP directly with no recreation of the Materials folder’s contents.
You seem to be running the installer every time you double-click a SKP file !
This is not how it’s supposed to be…
Select an existing SKP file’s icon and right-click > find the Open with… item in the context-menu.
There was a time when the list got messed up…
It should say ‘SketchUp 2021’, if you’ve somehow got it set to run the installer then that’s an issue !
Try choosing another app and choosing that as the default to open all double-clicked SKP files…
You can also do this via the Settings dialog… > Default Apps > Choose default app by file type…
Find .skp entry and ensure it points to SketchUp 2021
If for some reason it’s looking for the wrong thing and you can’t fix it, then Regedit might help but only go down that route if you are brave…
In regedit the .skp file-type’s opener FriendlyAppName should be ‘SketchUp 2021’ [note that this also applies to 2021 Layout & StyleBuilder files too]…