Are you are using SuccessFactors APIs (SFAPI/Odata API/Adhoc API) and have some integration scenario setup with your SFSF Instance and third party applications (benefits, payroll or timekeeping systems).
Are you using some middleware (eg: SAP CPI/HCI/PI/PO/XI or Dell Boomi) for integration setup. Note that for CPI, if you already have SuccessFactors' root certificate installed in your tenant, you won't be impacted.
For Boomi, if you are using the SFSF Hosted Cloud atom of the same DC where your instance resides, you need not make any changes. However, if you are using a local atom/Dell Atom Cloud in Boomi to connect to our APIs, you may need to upload the certificates in Boomi.
Is your Successfators API domain for which the certificate is being renewed (Eg: *.successfactors.eu) is same as the domain you are using to access/connect to Successfactors API server using API URL as the endpoint URL.
Is your Internal Identity Provider (Azure, ADFS or Okta) use SuccessFactors Certificate?
