You could follow these steps to reset the SSL certificate.
1. From the operation panel, enter Administrator mode.
2. Select Security Setting -> Security Details.
3. Page down to Initialize, select Network Settings; then press OK.
4. Recycle the MFP when complete. This will remove the certificate from the MFP and allow access to the MFP Administrator mode via a web browser.
If, when using the panel to turn off the SSL settings, the controls are not available then the protocol links are no longer valid and need to be rebuilt. This is because the links are pointing to the old certificate which is no longer installed on the MFP. Use the following procedure to create a new certificate and reorient the links to point them to the new certificate, making them valid and available.
1. Browse into the MFP using a web browser and enter Administrator mode.
2. Select Security -> PKI Setting and click the Display button.
3. Click the New Registration button.
4. Select Create and install a self-signed certificate.
5. Complete the form with the appropriate information and click the OK button. You should see a message "Certificate is being created" and then another message "Certificate has been created and installed. SSL/TLS can be used".
6. Click the OK button.
To overwrite the protocol links, use this procedure:
1. Select the Protocol Setting selection from the column on the left. A list of protocols is displayed.
2. Select the protocols that were previously linked to the old certificate. If this is unknown, the best practice is to select the TCP Socket and OpenAPI protocols.
3. For each protocol that does not have SSL control via the panel, click the Create button beside that protocol. A message is displayed to connect each protocol to the certificate.
4. Click OK. When complete, you will see an asterisk(*) beside each protocol enabled to use that certificate.
5. When complete, recycle the MFP.
You should now have access to the SSL settings for those protocols via the operation panel. You can then disable the SSL settings as desired, then remove the certificate, then install a new certificate.