[Owncloud] [OwnCloud 4] Calendar access via CalDav

[SEW-Webmaster]

Hello,

I just installed the new ownCloud 4 on my server. All requirements are
met as shown via the dependencies info application.

I use Thunderbird/Lightning to access the calendars via CalDav. I am
able to access the calendars of my administrator user via Thunderbird as
well as via browser after entering my credentials.

My problem is, that I am not able to access calendars of other users
which are not in the admin group. Neither Thunderbird nor a browser is
able to get access to it. However, the calendars are viewable via the
web interface of owncloud.
When I access the calendar via browser I get the following error message:

<d:error>
<s:exception>Sabre_DAV_Exception_NotAuthenticated</s:exception><s:message>Username
or password does not match</s:message>
<s:sabredav-version>1.6.2</s:sabredav-version>
</d:error>

The entered credentials are correct.

What can be the cause of this issue?

With best regards,
Sebastian