Starting yesterday in our corporate office (all sharing the same internet connection) we found two PCs suddenly are not syncing with Dropbox anymore, showing the well known “Can’t establish secure internet connection” error.
Other PCs work normally.
We are located in Germany and using Windows 8.1 PCs. All Dropbox clients are up-to-date (version 3.2.4).
Upon further investigation and using Process Monitor from SysInternals I found that the erronous PCs create connections to CloudFront servers while the working ones don’t.
An example would be
When entering the URL https://server-54-230-198-253.lhr50.r.cloudfront.net into my browser, I get an error
While I don’t know whether my investigation is actually related to the error, I still want to report it here.
When entering the mentioned server into an online SSL validator, it says:
No SSL certificates were found on server-54-230-198-253.lhr50.r.cloudfront.net. Make sure that the name resolves to the correct server and that the SSL port (default is 443) is open on your server’s firewall.
The solution was actually simple, once we figured out:
- Log the client off from Dropbox
- Log in as another Dropbox user
- Log that other Dropbox user off again from the client
- Log in the original Dropbox user which failed initially
Now the sync works again. Verified for two PCs. Also the erroneous server-54-230-198-253.lhr50.r.cloudfront.net URL is not contacted anymore.
The Dropbox support was just as you would expect: Sending late, unhelpful robot texts, claiming I was too stupid to read the documentation or have a working firewall.
So still great product, although aweful support.