Sync client: Access forbidden by server

I’m trying to configure the Zimbra drive addon with NextCloud and everything works except for the sync clients.

NextCloud Server: Verson 13.0.4

NextCloud Client: Version 2.3.3

Zimbra Server:  Version 8.8.6_GA_1906.RHEL7_64_20171130041047 RHEL7_64 FOSS edition.

Zimbra Drive Extension: Version 8.7.10

Both the Zimbra server and the NextCloud servers are configured with proper DNS and TLS (SSL Certificates)

What Works

  • I’m able to log into the NextCloud web interface using a Zimbra domain account (
  • From within Zimbra I am able to browse, upload, download and delete files using the Zimbra Drive Extension
  • Output of the Zimbra Drive Test:
[OK] Zimbra Drive app installation test : Zimbra Drive app is installed.
[OK] Enabled Zimbra's users test : Zimbra's users are enabled.
[OK] Enabled Zimbra's user login : Zimbra Drive authentication is enabled.
[OK] Is server url set test : The server url is set.
[OK] Is server port set test : The server port is set.
[OK] Zimbra host connection test : Zimbra Drive app can reach the host.
[OK] Zimbra authentication page connection test : Zimbra Drive app can reach Zimbras authentication page.
[OK] Zimbra Drive extension connection test : Zimbra Drive app can reach Zimbra Drive extension.

What Doesn’t Work

  • I’m unable to create an account in the NextCloud Sync Client (Windows or Linux) with a valid Zimbra user account.
    Here’s the Error on the sync client:
Access forbidden by server.  To verify that you have proper access, click here to access the service with your browser.

Is there a configuration that might be missing? It’s strange that authentication works fine through the web interface but not through the sync client.

Any suggestions would be appreciated!

Solved it!

It turns out that it didn’t like that there was already a NextCloud user with the username that was the account name (without the part).

I deleted that user and was able to successfully add the account to the sync client.