On Quickbooks 2013 Capital One now gives the message "Unsupported browser" when trying to download Capital One transactions. However, I'm running IE 11 on Windows Server 2012. Users have reported that this problem persists on all newer version of Quickbooks up through Quickbooks 2016. (https://community.intuit.com/questions/1025880-capitol-one-now-blocks-quickbooks-transaction-downloads-due-to-outdated-qb-browser)
Additionally, the problem does not happen if you download the Capital one charges outside of Quickbooks and import them a s a QBO file. It only happens with the embedded browser in Quickbooks.