Due to a recent Google Sheets update, Google Chrome users must be signed into the same profile in both Sheets and Chrome in order to access add-ons. If you're reading this article, you were probably navigated here because your Sheets and Chrome profiles are mismatched.
This tends to occur when users log in to Chrome with a different (personal) email as their Google credentials for that session. When they do that, it can create challenges for Google add-ons that use a different email than that one for authentication.
How to Sign in to Chrome
Click the profile icon at the top right of Chrome
Click + Add
Sign in to Chrome using the email associated with your Cube account (i.e. your work email)