Google Chrome "ERR_SSL_KEY_USAGE_INCOMPATIBLE" Google Chrome recently rolled out an update that went live for most users this morning. That update adds new security requirements that prevent it from connecting to webservers running on IIS with self-signed SSL certificates with default settings.

This is a recent change in Microsoft Edge. In essence, connections which fail this check will fail with the error ERR_SSL_KEY_USAGE_INCOMPATIBLE. Sites which fail with this error likely have a misconfigured certificate.

Scroll to the bottom of the page, then select Advanced. Scroll down to the Reset and clean up section, then select Clean up computer. Select Find. You should see a message that reads, "Checking for harmful software." This process can take several minutes to complete.