Hi Victoria,
Please try the following steps to re-install the OneDrive for Business Mac sync client and let us know the result:
1. Exit the app completely.
2. Move the app to Trash.
3. Go up to the Menu bar > Go > Go to Folder... > type in ~/library/Application Support > Go.
4. Find and remove the OneDriveBusiness folder.
5. Re-install the app.
In addition, please capture a screenshot of the error message from the app and post back. We will look into the issue further.
To insert a screenshot, please click Use rich formatting>
Insert/Edit Media > Browse... > Insert.
Feel free to share any updates with us.
Best regards,
Rachel Zhang