I am experiencing the same problem as described in Tasks are not synchronized: DUE must not be < DTSTART.
Sadly, I have quite a few tasks, so that going over each item one by one to find the faulty one is not practical. So right now, I’m left with no working sync.
I would like to suggest two things Improve logging to a point where I can easily identify the faulty task. The log output could just also dump the plain text it’s trying to parse below the stack trace. That would be immensely helpful. Other helpful Solutions would be to include the faulty timestamps if it’s easier. Basically: include anything that allows me to narrow down the faulty tasks. (From the stack trace i’m not sure it falls within the domain of DAVdroid.) I do realize that DUE < DTSTART is against the specs. Warn about it all you want. But please don’t throw everything else under the bus by throwing an exception. Steps to reproduce Have a VTODO on your server that has DUE < DTSTART. Sync See this message in your notification area0_1475660035809_sync-fail-notification.png See this log messageSYNCHRONIZATION INFO Synchronization phase: 9 Account name: ---redacted--- Authority: org.dmfs.tasks EXCEPTION: java.lang.IllegalArgumentException: DUE must not be < DTSTART at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:165) at android.database.DatabaseUtils.readExceptionWithOperationApplicationExceptionFromParcel(DatabaseUtils.java:158) at android.content.ContentProviderProxy.applyBatch(ContentProviderNative.java:520) at android.content.ContentProviderClient.applyBatch(ContentProviderClient.java:418) at at.bitfire.ical4android.BatchOperation.runBatch(BatchOperation.java:86) at at.bitfire.ical4android.BatchOperation.commit(BatchOperation.java:58) at at.bitfire.ical4android.AndroidTask.update(AndroidTask.java:237) at at.bitfire.davdroid.syncadapter.TasksSyncManager.processVTodo(TasksSyncManager.java:205) at at.bitfire.davdroid.syncadapter.TasksSyncManager.downloadRemote(TasksSyncManager.java:145) at at.bitfire.davdroid.syncadapter.SyncManager.performSync(SyncManager.java:170) at at.bitfire.davdroid.syncadapter.TasksSyncAdapterService$SyncAdapter.onPerformSync(TasksSyncAdapterService.java:78) at android.content.AbstractThreadedSyncAdapter$SyncThread.run(AbstractThreadedSyncAdapter.java:272) SOFTWARE INFORMATION DAVdroid version: 1.3.1-ose (116) Wed Sep 21 08:17:52 GMT+02:00 2016 Installed from: org.fdroid.fdroid JB Workaround installed: no CONFIGURATION System-wide synchronization: automatically Account: ---redacted--- Address book sync. interval: x min Calendar sync. interval: x min OpenTasks sync. interval: x min WiFi only: x [CardDAV] Contact group method: CATEGORIES RFC 6868 encoding: x [CalDAV] Time range (past days): x Manage calendar colors: x SQLITE DUMP android_metadata | locale | | x | ---------- settings | setting | value | | hint_OpenTasksNotInstalled | 0 | ---------- services | _id | accountName | service | principal | | 3 | ---redacted--- | carddav | ---redacted--- | | 4 | ---redacted--- | caldav | ---redacted--- | ---------- sqlite_sequence | name | seq | | services | 4 | | collections | 52 | | homesets | 11 | ---------- homesets | _id | serviceID | url | | 10 | 4 | ---redacted--- | | 11 | 3 | ---redacted--- | ---------- collections | _id | serviceID | url | readOnly | displayName | description | color | timezone | supportsVEVENT | supportsVTODO | sync | | 44 | 4 | ---redacted--- | 1 | ---redacted--- | ---redacted--- | -54 | <null> | 1 | 1 | 0 | | 45 | 4 | ---redacted--- | 0 | ---redacted--- | ---redacted--- | -6306073 | <null> | 1 | 1 | 1 | | 46 | 4 | ---redacted--- | 0 | ---redacted--- | ---redacted--- | -1146130 | <null> | 1 | 1 | 1 | | 47 | 4 | ---redacted--- | 0 | ---redacted--- | ---redacted--- | -16777216 | <null> | 1 | 1 | 1 | | 48 | 4 | ---redacted--- | 0 | ---redacted--- | ---redacted--- | -1605516 | <null> | 1 | 1 | 1 | | 49 | 4 | ---redacted--- | 0 | ---redacted--- | ---redacted--- | -8355840 | <null> | 1 | 1 | 1 | | 50 | 4 | ---redacted--- | 0 | ---redacted--- | ---redacted--- | -4989844 | <null> | 1 | 1 | 1 | | 51 | 4 | ---redacted--- | 1 | ---redacted--- | ---redacted--- | -32944 | <null> | 1 | 1 | 1 | | 52 | 3 | ---redacted--- | 0 | ---redacted--- | ---redacted--- | <null> | <null> | <null> | <null> | 1 | ---------- SYSTEM INFORMATION Android version: 6.0.1 (---redacted---) Device: ---redacted---
