This article provides instructions to remove 6sense cookies, which can solve many errors in the product. These instructions are for Google Chrome, but the process is similar in other browsers.
First, while on the 6sense platform, click on the lock icon beside the URL and select Cookies.
Next, click the Remove button in the window that pops up to delete all cookies for 6sense.com.
This will log you out from the 6sense platform and resolve any bad cookie issues.