Hidden Salesforce fields during CRM sync often cause an error message to appear, and lead to seats not syncing.
If some necessary Salesforce fields are hidden, the error message, Could not read the required Salesforce fields from your org. Please refer to the security whitepaper provided by your LinkedIn CSM appears when attempting to enable sync for an individual user.
As an admin, you can fix this issue by ensuring that all necessary Salesforce fields are not hidden and are saved as Editable. Some of these fields include: