Hi,
after upgrading to 1.0.8, my connection to my mail.de calender/contacts were broken.
I removed all the app data and app itself and after a clean install, I tried to add a new account using email/password of my (mail.de account).
My problem looks quite similar to the one here.
But I can’t force mail.de to modify their installation to shut off http/2 
This is what I get:
LOGS:
2016-05-07 10:30:41 1 [ui.setup.DavResourceFinder] Finding initial carddav service configuration
2016-05-07 10:30:41 1 [ui.setup.DavResourceFinder] No principal found at user-given URL, trying to discover
2016-05-07 10:30:41 1 [ui.setup.DavResourceFinder] Looking up SRV records for _carddavs._tcp.mail.de
2016-05-07 10:30:41 1 [ui.setup.DavResourceFinder] Found carddav service at https://adressbuch.mail.de:443
2016-05-07 10:30:41 1 [ui.setup.DavResourceFinder] Trying to determine principal from initial context path=https://adressbuch.mail.de/.well-known/carddav
2016-05-07 10:30:41 1 [HttpClient$1] --> PROPFIND https://adressbuch.mail.de/.well-known/carddav http/1.1
2016-05-07 10:30:41 1 [HttpClient$1] Content-Type: application/xml; charset=utf-8
2016-05-07 10:30:41 1 [HttpClient$1] Content-Length: 198
2016-05-07 10:30:41 1 [HttpClient$1] Depth: 0
2016-05-07 10:30:41 1 [HttpClient$1]
2016-05-07 10:30:41 1 [HttpClient$1] <?xml version='1.0' encoding='UTF-8' ?><propfind xmlns="DAV:" xmlns:CAL="urn:ietf:params:xml:ns:caldav" xmlns:CARD="urn:ietf:params:xml:ns:carddav"><prop><current-user-principal /></prop></propfind>
2016-05-07 10:30:41 1 [HttpClient$1] --> END PROPFIND (198-byte body)
2016-05-07 10:31:11 1 [ui.setup.DavResourceFinder] carddav service discovery failed
EXCEPTION java.net.SocketTimeoutException: timeout
at okhttp3.internal.framed.FramedStream$StreamTimeout.newTimeoutException(FramedStream.java:600)
at okhttp3.internal.framed.FramedStream$StreamTimeout.exitAndThrowIfTimedOut(FramedStream.java:608)
at okhttp3.internal.framed.FramedStream$FramedDataSink.emitDataFrame(FramedStream.java:505)
at okhttp3.internal.framed.FramedStream$FramedDataSink.close(FramedStream.java:545)
at okio.RealBufferedSink.close(RealBufferedSink.java:241)
at okhttp3.internal.http.HttpEngine$NetworkInterceptorChain.proceed(HttpEngine.java:705)
at at.bitfire.davdroid.HttpClient$PreemptiveAuthenticationInterceptor.intercept(HttpClient.java:153)
at okhttp3.internal.http.HttpEngine$NetworkInterceptorChain.proceed(HttpEngine.java:681)
at at.bitfire.davdroid.HttpClient$UserAgentInterceptor.intercept(HttpClient.java:139)
at okhttp3.internal.http.HttpEngine$NetworkInterceptorChain.proceed(HttpEngine.java:681)
at okhttp3.internal.http.HttpEngine.readResponse(HttpEngine.java:563)
at okhttp3.RealCall.getResponse(RealCall.java:241)
at okhttp3.RealCall$ApplicationInterceptorChain.proceed(RealCall.java:198)
at okhttp3.logging.HttpLoggingInterceptor.intercept(HttpLoggingInterceptor.java:203)
at okhttp3.RealCall$ApplicationInterceptorChain.proceed(RealCall.java:187)
at okhttp3.RealCall.getResponseWithInterceptorChain(RealCall.java:160)
at okhttp3.RealCall.execute(RealCall.java:57)
at at.bitfire.dav4android.DavResource.propfind(DavResource.java:264)
at at.bitfire.davdroid.ui.setup.DavResourceFinder.getCurrentUserPrincipal(DavResourceFinder.java:329)
at at.bitfire.davdroid.ui.setup.DavResourceFinder.discoverPrincipalUrl(DavResourceFinder.java:311)
at at.bitfire.davdroid.ui.setup.DavResourceFinder.findInitialConfiguration(DavResourceFinder.java:137)
at at.bitfire.davdroid.ui.setup.DavResourceFinder.findInitialConfiguration(DavResourceFinder.java:87)
at at.bitfire.davdroid.ui.setup.DetectConfigurationFragment$ServerConfigurationLoader.loadInBackground(DetectConfigurationFragment.java:143)
at at.bitfire.davdroid.ui.setup.DetectConfigurationFragment$ServerConfigurationLoader.loadInBackground(DetectConfigurationFragment.java:126)
at android.support.v4.content.AsyncTaskLoader.onLoadInBackground(AsyncTaskLoader.java:296)
at android.support.v4.content.AsyncTaskLoader$LoadTask.doInBackground(AsyncTaskLoader.java:54)
at android.support.v4.content.AsyncTaskLoader$LoadTask.doInBackground(AsyncTaskLoader.java:42)
at android.support.v4.content.ModernAsyncTask$2.call(ModernAsyncTask.java:128)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:818)
2016-05-07 10:31:11 1 [ui.setup.DavResourceFinder] Finding initial caldav service configuration
2016-05-07 10:31:11 1 [ui.setup.DavResourceFinder] No principal found at user-given URL, trying to discover
2016-05-07 10:31:11 1 [ui.setup.DavResourceFinder] Looking up SRV records for _caldavs._tcp.mail.de
2016-05-07 10:31:11 1 [ui.setup.DavResourceFinder] Found caldav service at https://kalender.mail.de:443
2016-05-07 10:31:11 1 [ui.setup.DavResourceFinder] Trying to determine principal from initial context path=https://kalender.mail.de/.well-known/caldav
2016-05-07 10:31:11 1 [HttpClient$1] --> PROPFIND https://kalender.mail.de/.well-known/caldav http/1.1
2016-05-07 10:31:11 1 [HttpClient$1] Content-Type: application/xml; charset=utf-8
2016-05-07 10:31:11 1 [HttpClient$1] Content-Length: 198
2016-05-07 10:31:11 1 [HttpClient$1] Depth: 0
2016-05-07 10:31:11 1 [HttpClient$1]
2016-05-07 10:31:11 1 [HttpClient$1] <?xml version='1.0' encoding='UTF-8' ?><propfind xmlns="DAV:" xmlns:CAL="urn:ietf:params:xml:ns:caldav" xmlns:CARD="urn:ietf:params:xml:ns:carddav"><prop><current-user-principal /></prop></propfind>
2016-05-07 10:31:11 1 [HttpClient$1] --> END PROPFIND (198-byte body)
2016-05-07 10:31:12 1 [ui.setup.DavResourceFinder] caldav service discovery failed
EXCEPTION java.io.IOException: stream was reset: REFUSED_STREAM
at okhttp3.internal.framed.FramedStream.getResponseHeaders(FramedStream.java:145)
at okhttp3.internal.http.Http2xStream.readResponseHeaders(Http2xStream.java:149)
at okhttp3.internal.http.HttpEngine.readNetworkResponse(HttpEngine.java:723)
at okhttp3.internal.http.HttpEngine.access$200(HttpEngine.java:81)
at okhttp3.internal.http.HttpEngine$NetworkInterceptorChain.proceed(HttpEngine.java:708)
at at.bitfire.davdroid.HttpClient$PreemptiveAuthenticationInterceptor.intercept(HttpClient.java:153)
at okhttp3.internal.http.HttpEngine$NetworkInterceptorChain.proceed(HttpEngine.java:681)
at at.bitfire.davdroid.HttpClient$UserAgentInterceptor.intercept(HttpClient.java:139)
at okhttp3.internal.http.HttpEngine$NetworkInterceptorChain.proceed(HttpEngine.java:681)
at okhttp3.internal.http.HttpEngine.readResponse(HttpEngine.java:563)
at okhttp3.RealCall.getResponse(RealCall.java:241)
at okhttp3.RealCall$ApplicationInterceptorChain.proceed(RealCall.java:198)
at okhttp3.logging.HttpLoggingInterceptor.intercept(HttpLoggingInterceptor.java:203)
at okhttp3.RealCall$ApplicationInterceptorChain.proceed(RealCall.java:187)
at okhttp3.RealCall.getResponseWithInterceptorChain(RealCall.java:160)
at okhttp3.RealCall.execute(RealCall.java:57)
at at.bitfire.dav4android.DavResource.propfind(DavResource.java:264)
at at.bitfire.davdroid.ui.setup.DavResourceFinder.getCurrentUserPrincipal(DavResourceFinder.java:329)
at at.bitfire.davdroid.ui.setup.DavResourceFinder.discoverPrincipalUrl(DavResourceFinder.java:311)
at at.bitfire.davdroid.ui.setup.DavResourceFinder.findInitialConfiguration(DavResourceFinder.java:137)
at at.bitfire.davdroid.ui.setup.DavResourceFinder.findInitialConfiguration(DavResourceFinder.java:88)
at at.bitfire.davdroid.ui.setup.DetectConfigurationFragment$ServerConfigurationLoader.loadInBackground(DetectConfigurationFragment.java:143)
at at.bitfire.davdroid.ui.setup.DetectConfigurationFragment$ServerConfigurationLoader.loadInBackground(DetectConfigurationFragment.java:126)
at android.support.v4.content.AsyncTaskLoader.onLoadInBackground(AsyncTaskLoader.java:296)
at android.support.v4.content.AsyncTaskLoader$LoadTask.doInBackground(AsyncTaskLoader.java:54)
at android.support.v4.content.AsyncTaskLoader$LoadTask.doInBackground(AsyncTaskLoader.java:42)
at android.support.v4.content.ModernAsyncTask$2.call(ModernAsyncTask.java:128)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:818)
SOFTWARE INFORMATION
DAVdroid version: 1.0.8 (99) Wed Apr 27 09:44:38 MESZ 2016
Installed from: org.fdroid.fdroid
JB Workaround installed: no
CONFIGURATION
System-wide synchronization: automatically
SQLITE DUMP
android_metadata
| locale |
| de_DE |
----------
settings
| setting | value |
| hint_OpenTasksNotInstalled | 0 |
----------
services
| _id | accountName | service | principal |
----------
sqlite_sequence
| name | seq |
----------
homesets
| _id | serviceID | url |
----------
collections
| _id | serviceID | url | readOnly | displayName | description | color | timezone | supportsVEVENT | supportsVTODO | sync |
----------
SYSTEM INFORMATION
Android version: 5.1.1 (LMY49H)
Device: Zuk Z1 (Z1)
So now my contacts/calendars on my cell phone are useless / non-functioning any more. Grrrr.
What to do now?
Bernd
