“Private key is missing or invalid when importing a certificate” in Google Chrome
You may be trying to do is add it to the wrong certificate store. If you’re attempting to add it under «Your Certificates», you’re gonna have a bad time. That tab is for adding identity certificates; what your browser offers to the server to establish the browser’s identity.
To trust the self-signed cert that will be on your server end. If that’s the case, you need to add it in your «Authorities» tab.