Hi everyone,
just finished setting up my new FP6+, but I ran into a few problems during DAVx5 setup. I’ve been using it on my FP3+ reliably for years to sync with my Synology DS Calendar app. On my new phone, I can’t set up the sync account, due to errors during CalDAV service detection.
I tried the same on my old phone and it works like a charm, so the Synology side is exonerated. But I’m truly puzzled what the issue could be on the FP6+. All required input, i.e. base URL, username, password, are verified and 100% correct. But somehow the authentication seems to fail. So I’m guessing that the FP6+ handles it differently than the FP3+. No idea as to how or why.
Has anyone had the same issue and found a solution for it? Any pointers would be greatly appreciated.
Thanks and Best Regards.
Logs
Debug log (truncated, links removed due to posting restrictions):
2026-09-29 10:30:52 2 [.davdroid.servicedetection.DavResourceFinder] Finding initial carddav service configuration
2026-09-29 10:30:52 2 [.davdroid.servicedetection.DavResourceFinder] Checking user-given URL: https://mysynstation/caldav
2026-09-29 10:30:52 2 [.davdroid.network.HttpClientBuilder] → PROPFIND https://mysynstation/caldav
Content-Type: application/xml; charset=UTF-8
Content-Length: 290
Depth: 0
Accept: application/xml, text/xml
Accept-Language: en-DE, en;q=0.7, *;q=0.5
Authorization: ██
User-Agent: DAVx5/4.5.19-ose (at.bitfire.davdroid)
Accept-Encoding: gzip,deflate,identity
- → END PROPFIND (290-byte body)
2026-09-29 10:30:52 2 [.davdroid.network.HttpClientBuilder] ← 405 (337ms)
content-length: 150
content-type: text/html
date: Tue, 29 Sep 2026 08:30:53 GMT
strict-transport-security: max-age=15768000; includeSubdomains; preload
405 Not Allowed
nginx
← END HTTP (337ms, 150-byte body)
2026-09-29 10:30:52 2 [.davdroid.servicedetection.DavResourceFinder] PROPFIND/OPTIONS on user-given URL failed
EXCEPTION at.bitfire.dav4jvm.ktor.exception.HttpException: HTTP 405 Method Not Allowed
at at.bitfire.dav4jvm.ktor.exception.HttpException$Companion.fromResponse(r8-map-id-029b39f3298062b478087a2a6c96dba488f1ac5427a260c20736f9c96c86e3c1:206)
at at.bitfire.dav4jvm.ktor.exception.HttpException$Companion$fromResponse$1.invokeSuspend(r8-map-id-029b39f3298062b478087a2a6c96dba488f1ac5427a260c20736f9c96c86e3c1:13)
at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(r8-map-id-029b39f3298062b478087a2a6c96dba488f1ac5427a260c20736f9c96c86e3c1:8)
at kotlinx.coroutines.DispatchedTask.run(r8-map-id-029b39f3298062b478087a2a6c96dba488f1ac5427a260c20736f9c96c86e3c1:114)
at android.os.Handler.handleCallback(Handler.java:995)
at android.os.Handler.dispatchMessage(Handler.java:103)
at android.os.Looper.loopOnce(Looper.java:248)
at android.os.Looper.loop(Looper.java:338)
at android.app.ActivityThread.main(ActivityThread.java:9137)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:616)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:940)
2026-09-29 10:30:52 2 [.davdroid.network.HttpClientBuilder] → PROPFIND
Content-Length: 198
Depth: 0
Accept: application/xml, text/xml
Accept-Language: en-DE, en;q=0.7, *;q=0.5
Authorization: ██
User-Agent: DAVx5/4.5.19-ose (at.bitfire.davdroid)
Accept-Encoding: gzip,deflate,identity
- → END PROPFIND (198-byte body)
2026-09-29 10:30:53 2 [.davdroid.network.HttpClientBuilder] ← 302 (67ms)
content-length: 138
content-type: text/html
date: Tue, 29 Sep 2026 08:30:53 GMT
location:
strict-transport-security: max-age=15768000; includeSubdomains; preload
302 Found
nginx
← END HTTP (67ms, 138-byte body)
2026-09-29 10:30:53 2 [.davdroid.network.HttpClientBuilder] → PROPFIND
Content-Type: application/xml; charset=UTF-8
Content-Length: 198
Depth: 0
Accept: application/xml, text/xml
Accept-Language: en-DE, en;q=0.7, *;q=0.5
Authorization: ██
User-Agent: DAVx5/4.5.19-ose (at.bitfire.davdroid)
Accept-Encoding: gzip,deflate,identity
- → END PROPFIND (198-byte body)
2026-09-29 10:30:55 2 [.davdroid.network.HttpClientBuilder] ← 401 (1928ms)
content-type: text/plain; charset=utf-8
date: Tue, 29 Sep 2026 08:30:55 GMT
strict-transport-security: max-age=15768000; includeSubdomains; preload
www-authenticate: Basic realm=“Radicale - Password Required”
Access to the requested resource forbidden.
← END HTTP (1928ms, 43-byte body)
2026-09-29 10:30:55 2 [.davdroid.network.HttpClientBuilder] → PROPFIND
Content-Type: application/xml; charset=UTF-8
Content-Length: 198
Depth: 0
Accept: application/xml, text/xml
Accept-Language: en-DE, en;q=0.7, *;q=0.5
User-Agent: DAVx5/4.5.19-ose (at.bitfire.davdroid)
Accept-Encoding: gzip,deflate,identity
Authorization: ██
- → END PROPFIND (198-byte body)
2026-09-29 10:30:56 2 [.davdroid.network.HttpClientBuilder] ← 401 (1321ms)
content-type: text/plain; charset=utf-8
date: Tue, 29 Sep 2026 08:30:56 GMT
strict-transport-security: max-age=15768000; includeSubdomains; preload
www-authenticate: Basic realm=“Radicale - Password Required”
Access to the requested resource forbidden.
← END HTTP (1321ms, 43-byte body)
2026-09-29 10:30:56 2 [.davdroid.servicedetection.DavResourceFinder] Well-known URL detection failed
EXCEPTION at.bitfire.dav4jvm.ktor.exception.UnauthorizedException: HTTP 401 Unauthorized
at at.bitfire.dav4jvm.ktor.exception.HttpException$Companion.fromResponse(r8-map-id-029b39f3298062b478087a2a6c96dba488f1ac5427a260c20736f9c96c86e3c1:90)
at at.bitfire.dav4jvm.ktor.exception.HttpException$Companion$fromResponse$1.invokeSuspend(r8-map-id-029b39f3298062b478087a2a6c96dba488f1ac5427a260c20736f9c96c86e3c1:13)
at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(r8-map-id-029b39f3298062b478087a2a6c96dba488f1ac5427a260c20736f9c96c86e3c1:8)
at kotlinx.coroutines.DispatchedTask.run(r8-map-id-029b39f3298062b478087a2a6c96dba488f1ac5427a260c20736f9c96c86e3c1:114)
at android.os.Handler.handleCallback(Handler.java:995)
at android.os.Handler.dispatchMessage(Handler.java:103)
at android.os.Looper.loopOnce(Looper.java:248)
at android.os.Looper.loop(Looper.java:338)
at android.app.ActivityThread.main(ActivityThread.java:9137)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:616)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:940)
2026-09-29 10:30:56 2 [.davdroid.servicedetection.DavResourceFinder] No principal found at user-given URL, trying to discover for domain mysynstation
2026-09-29 10:30:56 2 [.davdroid.servicedetection.DavResourceFinder] Looking up SRV/TXT records for _carddavs._tcp.mysynstation
2026-09-29 10:30:56 2 [.davdroid.servicedetection.DavResourceFinder] Didn’t find carddav service, trying at
2026-09-29 10:30:56 2 [.davdroid.servicedetection.DavResourceFinder] Trying to determine principal from initial context path=
2026-09-29 10:30:56 2 [.davdroid.network.HttpClientBuilder] → PROPFIND
Content-Type: application/xml; charset=UTF-8
Content-Length: 198
Depth: 0
Accept: application/xml, text/xml
Accept-Language: en-DE, en;q=0.7, *;q=0.5
Authorization: ██
User-Agent: DAVx5/4.5.19-ose (at.bitfire.davdroid)
Accept-Encoding: gzip,deflate,identity
- → END PROPFIND (198-byte body)