Hi sharyn1977,
Thank you for contacting Apple Support Communities. Based on what you stated, it seems like there is trouble with a keychain and an app. Try looking for a Microsoft SharePoint keychain and remove it and restart and test again to see if the issue persists.
"Delete a keychain
- In the Keychain Access app
on your Mac, if your keychains aren’t visible, choose Window > Keychain Access. - Select a keychain in the Keychains list.
- Choose File > Delete Keychain [keychain name].
- Click Delete References."
"Important: If you delete a keychain’s References and Files, all the information in the keychain is deleted. However, if you know the keychain’s password, you can recover the information."
Delete a keychain in Keychain Access on Mac - Apple Support
Please don't hesitate to let us know if you need additional assistance.
Cheers.