E/DBUtils ( 7561): No parent for record 4hnVOzVYVDw8 D/DBUtils ( 7561): Exception logging bookmark record null D/DBUtils ( 7561): java.lang.NullPointerException D/DBUtils ( 7561): at org.mozilla.gecko.sync.repositories.android.RepoUtils.logBookmark(RepoUtils.java:286) D/DBUtils ( 7561): at org.mozilla.gecko.sync.repositories.android.RepoUtils.bookmarkFromMirrorCursor(RepoUtils.java:281) D/DBUtils ( 7561): at org.mozilla.gecko.sync.repositories.android.AndroidBrowserBookmarksRepositorySession.recordFromMirrorCursor(AndroidBrowserBookmarksRepositorySession.java:231) D/DBUtils ( 7561): at org.mozilla.gecko.sync.repositories.android.AndroidBrowserRepositorySession.createRecordToGuidMap(AndroidBrowserRepositorySession.java:495) D/DBUtils ( 7561): at org.mozilla.gecko.sync.repositories.android.AndroidBrowserRepositorySession.putRecordToGuidMap(AndroidBrowserRepositorySession.java:508) D/DBUtils ( 7561): at org.mozilla.gecko.sync.repositories.android.AndroidBrowserBookmarksRepositorySession.insert(AndroidBrowserBookmarksRepositorySession.java:362) D/DBUtils ( 7561): at org.mozilla.gecko.sync.repositories.android.AndroidBrowserRepositorySession$1.run(AndroidBrowserRepositorySession.java:395) D/DBUtils ( 7561): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076) D/DBUtils ( 7561): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569) D/DBUtils ( 7561): at java.lang.Thread.run(Thread.java:856) -- Samsung Galaxy Nexus (Android 4.0.3) Mozilla/5.0 (Android; Linux armv7l; rv:12.0a1) Gecko/20120128 Firefox/12.0a1 Fennec/12.0a1

This is just a logged exception (within a log method!), not one that actually propagated anywhere. Still, the root cause is meaningful. Perhaps Fennec has started creating bookmarks without a parent?