Pydio cells-sync client can't connect

I installed pydio with cells v3 on my windows server behind nginx. The service is up and reachable from both the outside the network at and within my network using the servers local IP. From outside, SSL is working, from inside the self-issued SSL certificate is used and flaged as insecure.

The browser interface is working perfectly fine. However, I can’t log in using the win-desktop client or andriod app. Entering and clicking ‘Username’ opens the browser and I get a 520 ‘Web server is returning an unknown error.’ Before the error, the pydio interface is rendered for a few milliseconds:


Application is not yet connected to agent. Please wait
while we are trying to connect...

followed immediately by


Application is disconnected from agent. Please wait
while we are trying to reconnect...

However, the logs in the admin page don’t show any errors. Interestingly, when the 520 error is shown in the browser, the URL begins with, not

I have only mapped to internal-server-IP:8080 in nginx. Am I missing something here?

Hello @M_L
How did you configure the cells “Site” (./cells configure sites) : did you set the external URL to your ?

I had indeed not set it to though I was sure I did. I corrected the issue. The browser interface still works, the client still does not. It tries to reach http://localhost:3636/servers/external?manager= which shows the same messages from pydio and then a blank page instead of the SSL error.