That is a shame. No one seems to know what to do when this happens, and as usually happens with MS, they don't tell you what to do if something like this goes wrong, at least not in sufficient detail.

Did you look at Building Blocks & AutoText?

Yes; as far as I understood it, it didn't deal with the situation when the building blocks organizer is completely empty. Yet if you open built-in building blocks.dotx directly, all the building blocks are displayable.

Which Built-In Building Blocks.dotx file are you opening directly? You may have more than one on your system.

Are you opening the one in a subfolder of your program files folder, or the one that is in a subfolder of your AppData folder?

On my computer I have one at
C:\Program Files (x86)\Microsoft Office\Office14\Document Parts\1033\14
That is not the one that Word uses. Leave it alone!

There is a separate one at:
C:\Users\username\AppData\Roaming\Microsoft\Document Building Blocks\1033\14
This is a hidden system folder and you have to override Windows defaults to see it.
That is the file that should be renamed.

The latter is the one I have been dealing with. I haven't touched the other.

Have you tried renaming this file?

Yes, I have renamed the file, which had no effect.

And I have looked at live content\...\1033. I found the folder empty. The building blocks.dotx file that you indicate should be there isn't. I was surprised but did not know where to go from there and, to be truthful, did not know what to make of this.