A Microsoft file hosting and synchronization service.
Hello,
Just a quick heads up that this is a public community forum where users help each other, not official Microsoft support.
Looking at your screenshots, this looks like an account mismatch between a personal Microsoft account and a work or school account. In your fourth screenshot, the folder is hosted on personal OneDrive (live.com), but in the second screenshot, the invite is received by an institutional school email (office.com).
When the recipient clicks Sign in on that live.com page, the browser automatically tries to use their active school session credentials. Personal OneDrive cannot authenticate school or work accounts, which triggers that exact sign-in error.
Furthermore, personal OneDrive and school OneDrive run on completely separate platforms, which is why a folder shared from a personal account will never show up inside a school OneDrive app or under their shared files list.
To make sure we get this sorted out properly, could you confirm whether the recipient is trying to use their university school account or a personal Microsoft account (like Outlook.com or Hotmail)? Also, do you both have university Microsoft accounts that you could share between directly instead?