Is there a supported way to add a custom CA to Minitab’s certificate validation process?

Supported method

Yes. Minitab does not maintain its own trust store; it relies on the operating system’s certificate validation (Windows Certificate Manager) or, for older versions that bundle a Java runtime, the Java cacerts keystore.

Steps for Windows (current releases)

1. Obtain the CA certificate in .cer, .crt or .pem format.
2. Open certmgr.msc (or run mmc and add the Certificates snap‑in for the local machine).
3. Navigate to Trusted Root Certification Authorities → Certificates.
4. Right‑click → All Tasks → Import… and follow the wizard to place the certificate in the Trusted Root store.
5. Close the MMC.
6. Restart Minitab (close all instances and launch again) so it picks up the updated trust store.

Steps for older Minitab versions with bundled Java

1. Locate the JRE used by Minitab (usually ..\MinTab\jre\lib\security\cacerts).
2. Run keytool -import -alias myca -file ca.cer -keystore cacerts -storepass changeit (default password is changeit).
3. Restart Minitab.

Verification

• After restart, try to reach an internal HTTPS service that uses the custom CA (e.g., open the URL in Minitab’s web‑based help or a data‑import dialog).
• If the operation succeeds without a certificate warning, the CA is trusted.
• You can also check the Windows Event Viewer under Applications and Services Logs → Microsoft → Windows → TLS/Operational for any TLS handshake errors; absence of errors indicates success.
• As a quick cross‑check, open the same site in a browser; if the browser shows no certificate error, Minitab should behave similarly.

Notes and uncertainties

Minitab does not provide a UI or command‑line flag to reload the trust store without a restart; changes to the OS store are only read at process start. Future releases may add explicit configuration, but as of the latest public documentation no such mechanism is announced.