403 Forbidden error when connecting to Baïkal 0.2.7 server

[equaeghe]

From time to time, when connecting to a Baïkal 0.2.7 server, I get the error

REPORT https://baikal.<domain>/calcard.php/<resource type>/<username>/<resourcename>/ [HTTP/1.1 403 Forbidden <duration>ms]

This appears to be random and not have any repercussions.

Todo: find out whether this also happens with other servers.

[equaeghe]

In Chromium, I also get this error, but with more explanation:

REPORT https://baikal.<domain>/calcard.php/calendars/<username>/<resourcename>/ 403 (Forbidden)    jquery-2.1.3.min.js:4

with details

k.cors.a.crossDomain.send    jquery-2.1.3.min.js:4
n.extend.ajax    webdav_protocol.js:2980
CalDAVnetLoadCollection    webdav_protocol.js:2958
ajaxComplete    jquery-2.1.3.min.js:2
j    jquery-2.1.3.min.js:2
k.fireWith    jquery-2.1.3.min.js:4
x    jquery-2.1.3.min.js:4
(anonymous function)