These specific types of Generic Communication error: “General data transfer failure“ (no matter if it’s “Couldn't connect to server” or “Peer certificate cannot be authenticated with given CA certificates” occurs normally while performing an online activation/return. It is usually related with a communication error between the customer's PC and our License Server (https://license.proteinmetrics.com/).
In most of cases an offline activation/return solves the problem. In order to perform it, please follow steps detailed in sections 'Offline activation' or 'Offline return' respectively of User Guide .