The reason your Box Drive application is failing to connect is likely due to your company's proxy server blocking the application's communication, even though your web browser works fine. Your browser is configured to use the proxy, but the Box Drive ChoiceAdvantage application itself may not be, or the proxy is blocking the specific domains Box needs to complete its login and synchronization. The solution requires either manually configuring the proxy settings within Box Drive's configuration file or, more likely, having your company's IT department whitelist the necessary Box domains. Your best course of action is to contact IT and provide them with the list of domains to unblock.

Thank you for your reply.

But our company policy does not allow any Internet connection bypassing the proxy. So whitelisting is not an option.

Also, Windows is configured with system proxy and a properly programmed Windows app usually can use Kerberos to authenticate at the proxy and request user credentials.

We found that the Box Drive app is not properly authenticating at the proxy.

So can I configure the proxy manually somewhere? I could not find documentation or location of the config file. Preferrably without having to store user credentials but instead there should be a dialog asking me for the credentials every time I want to connect.

In the Box log, there is an entry:

“System.Net.WebException: The remote server returned an error: (407) Proxy Authentication Required.”

It looks like proxy is found, but the authentication is not handled correctly.