Please take a look at the following article from our Knowledge Base for information on resolving this issue.
https://support.presonus.com/hc/en-us/articles/360004609172-Why-am-I-receiving-an-error-message-when-activating-Studio-One-that-asks-me-to-log-into-my-presonus-com-and-agree-to-the-most-recent-terms-of-use-