Try another browser or a private or incognito browser window.
If the error occurs when using a specific link, try using a different link to achieve the same results, as a link that leads to a redirection loop can trigger the "bot" message.
More suggestions and discussion about this issue can be found in this thread:
It may or may not be an "eBay issue", but plenty of people can still sign in by using a private or incognito browser window, or by using a different browser, or by clearing cache and cookies. So you may want to try more than one thing before deciding there is nothing you can do about it.
