Hi, thanks for reaching out. When OneDrive stays stuck on “Loading,” it usually means your account or cached sign-in data needs to be refreshed. Are you signing in with a personal or work/school Microsoft account?
Try removing any saved OneDrive or Microsoft credentials in Windows Credential Manager, then restart your computer. After that, press Windows + R, type “onedrive /reset,” and press Enter to reset the app. Once it restarts, open OneDrive and sign in again. Also, make sure your Windows and Office updates are fully installed, as Microsoft notes that outdated versions can cause this issue.