We believe we have found the reason why you were not able to access the talks and lectures page. For some reason our website is only letting users access that mage in the language in which they registered in. So if you registered in Spanish then the link that will work for you is https://arkitekturo.com/es/competition/bauhaus-campus-2021/talks-lectures/. (notice the /es/ part).
We are working on fixing this, but until then the link above should work for you. Please let us know if it doesen’t.