CertSimple will be shutting down on January 30 2020. Read the announcement here.
If you lose your private key file, it's easily fixed.
Likewise, if you want to change your crypto (perhaps to support older devices like Windows XP or MacOS 10.9 that can't handle stronger ECC certs) you can also do this easily.
Just log in to our dashboard and click 'Fix a lost private key' on the left.