The same happened to me. I updated NextCloud from 10 to 11 (latest contacts app 1.5.2). Syncing worked fine for half an day and then suddenly I get this error while syncing contacts. It looks like Davdroid is sending invalid data to the server. Why does this happen and how can I correct this problem?
Thank you!
SYNCHRONIZATION INFO
Synchronization phase: 4
Account name: xxxxx@xxxx.de
Authority: com.android.contacts
HTTP REQUEST:
PUT /oc/remote.php/dav/addressbooks/users/xxxxx/contacts/119F383B20BA45BFB3374CB03B7A6CD8.vcf
If-Match: “8904941033fe86c4dd664f723bd63789”
BEGIN:VCARD[CR][LF]
VERSION:4.0[CR][LF]
PRODID:+//IDN bitfire.at//DAVdroid/1.3.4.1-gplay vcard4android ez-vcard/0.1[CR][LF]
0.0[CR][LF]
X-GENDER:M[CR][LF]
X-ABUID:119F383B20BA45BFB3374CB03B7A6CD8\:ABPerson[CR][LF]
REV;VALUE=timestamp:2016-11-07T05:09:31.252Z[CR][LF]
davdroid1.X-ABLabel:Home[CR][LF]
UID:119F383B20BA45BFB3374CB03B7A6CD8[CR][LF]
FN:xxxx/xxxx (xxxxx) xxxx[CR][LF]
N:xxx;xxx/xxx;(xxx);;[CR][LF]
TEL;TYPE=voice:+49 151 1111111111[CR][LF]
davdroid1.EMAIL;TYPE=x-home:xxxxx@xxxx.de[CR][LF]
REV:20161215T122225Z[CR][LF]
END:VCARD[CR][LF]
HTTP RESPONSE:
http/1.1 415 Unsupported Media Type
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Content-Length: 286
Content-Security-Policy: default-src ‘none’;
Content-Type: application/xml; charset=utf-8
Date: Thu, 15 Dec 2016 12:22:26 GMT
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Pragma: no-cache
Server: Microsoft-IIS/8.5
Set-Cookie: nc_username=deleted; expires=Thu, 01-Jan-1970 00:00:01 GMT; Max-Age=0; path=/oc; secure; httponly
Set-Cookie: nc_token=deleted; expires=Thu, 01-Jan-1970 00:00:01 GMT; Max-Age=0; path=/oc; secure; httponly
Set-Cookie: nc_session_id=deleted; expires=Thu, 01-Jan-1970 00:00:01 GMT; Max-Age=0; path=/oc; secure; httponly
Set-Cookie: nc_username=deleted; expires=Thu, 01-Jan-1970 00:00:01 GMT; Max-Age=0; path=/oc/; secure; httponly
Set-Cookie: nc_token=deleted; expires=Thu, 01-Jan-1970 00:00:01 GMT; Max-Age=0; path=/oc/; secure; httponly
Set-Cookie: nc_session_id=deleted; expires=Thu, 01-Jan-1970 00:00:01 GMT; Max-Age=0; path=/oc/; secure; httponly
Set-Cookie: ocac215dd5d7=1p3ktgp0sp4n7jl26q2qgb3fp5; path=/oc; secure; HttpOnly
X-Powered-By: PHP/5.6.29
X-Powered-By: ARR/2.5
X-Powered-By: ASP.NET
<?xml version=“1.0” encoding=“utf-8”?>[LF]
<d:error xmlns:d=“DAV:” xmlns:s=“http://sabredav.org/ns”>[LF]
<s:exception>Sabre\DAV\Exception\UnsupportedMediaType</s:exception>[LF]
<s:message>Validation error in vCard: REV MUST NOT appear more than once in a VCARD component</s:message>[LF]
</d:error>[LF]