Sims 4: Pressing "Save" doesn't do anything.

Lancasterj13  To test a few issues at once, please create a new admin Windows account on your computer and try playing there.  Make it local, as in, don't link it to your Microsoft account or any email address.  You'll be able to open the game without reinstalling anything, but your existing saves and other user data won't be available.

If saving works, restart your computer and try again, still in this new Windows account, to make sure nothing changes.  For example, an antivirus might interfere with the game only the second time it opens.