"Unable to save to game folder" issue.

I'm trying to make a simple recolor of an existing object, but when I go to save my work, I'm getting an "Unable to save to game folder" issue. I searched the forums and found others with this problem but wasn't able to find a solution. This is on a legitimate Origin copy of the game, not a pirated one.

Repro steps:

1. Freshly installed version, downloaded last night (June 1st)

2. Paths are pointing at the correct locations: D:\Origin\The Sims 4\ (that's where I installed Origin) and C\Users\MYUSERNAME\Documents\Electronic Arts\The Sims 4\

3. Click Object / Standalone Recolor.

4. Save the package file somewhere. (does it matter where?)

5. Pick literally any object to base it on.

6. Immediately click Save, no changes.

7. "Unable to save in your game folder."

There's nothing in the sims4studio log file indicating what could be wrong.

Can anyone assist? Thank you!