Box for Salesforce - "Invalid Login Credentials"

Box for Salesforce users may see the error message "Invalid Login Credentials" when attempting to view Box embed section within Salesforce record page:

Root Cause

This error typically occurs due to missing custom subdomain settings (i.e. Custom subdomain field is blank).

Resolution

To resolve this error, you need to follow the following steps to create a Custom Settings for override url.

1. Click on Setup at the top right corner
2. Enter Custom Settings in the Quick Find box,
3. Select Custom Settings.
4. From the Custom Settings page, click "Manage" next to the Folder Details row, and choose "New" in the Folder Details page.
   
5. For the Name field, use root_url_override, and for FolderId use https://box.app.box.com (or https://box.ent.box.com if you are a Box Verified Enterprise customer),  then click Save.
   

Alternatively, you can set up a custom subdomain on Admin Console (instead of leaving it blank), and populate "Box Enterprise Sub-Domain" with the same string on "Box Settings" tab on Salesforce.