Silent import failure

[ghost]

Hi, I have two droids with offlincalendars and this app, trying to exchange calendar events between them by exporting, sending by email and importing on the other device.

Everything works flawlessly, the import file is selected, 105 events processed and afterwards 105 events are shown for the offline calendar.

However those 105 events never land in the offline calendar. They are not displayed in the calendar app and if I invoke calendar-import-export again it shows 0 entries for the local calendar.

Looking at adb logcat didn't show anything obvious either. The only thing remotely related that I noticed was

I/ActivityManager( 2148): Start proc 26904:com.plusonelabs.calendar/u0a27 for broadcast com.plusonelabs.calendar/.EventAppWidgetProvider
D/droidparts-battery-widget( 2330): widgets updated
V/AlarmManager( 2148): done {29818533, alarm:android.intent.action.TIME_TICK} [187ms]
I/CastDatabase(25368): Saving the database
I/SQLiteCastStore(25368): Saving 0 CastNetworkInfo instances, 0 CastDeviceInfo instances, 0 paired guest mode devices.
E/SQLiteCastStore(25368): End saving paired guest mode devices
E/loadInstances(26904): widgetId:24
E/loadInstances(26904): java.io.FileNotFoundException: /data/data/com.plusonelabs.calendar/shared_prefs/instanceSettings24.json: open failed: ENOENT (No such file or directory)
E/loadInstances(26904): at libcore.io.IoBridge.open(IoBridge.java:456)
E/loadInstances(26904): at java.io.FileInputStream.(FileInputStream.java:76)
E/loadInstances(26904): at com.plusonelabs.calendar.prefs.SettingsStorage.getBytes(SettingsStorage.java:99)
E/loadInstances(26904): at com.plusonelabs.calendar.prefs.SettingsStorage.utf8File2String(SettingsStorage.java:91)
E/loadInstances(26904): at com.plusonelabs.calendar.prefs.SettingsStorage.getJSONObject(SettingsStorage.java:79)
E/loadInstances(26904): at com.plusonelabs.calendar.prefs.SettingsStorage.loadJson(SettingsStorage.java:42)
E/loadInstances(26904): at com.plusonelabs.calendar.prefs.InstanceSettings.ensureInstancesAreLoaded(InstanceSettings.java:103)
E/loadInstances(26904): at com.plusonelabs.calendar.prefs.InstanceSettings.fromId(InstanceSettings.java:74)
E/loadInstances(26904): at com.plusonelabs.calendar.EventAppWidgetProvider.onUpdate(EventAppWidgetProvider.java:51)
E/loadInstances(26904): at android.appwidget.AppWidgetProvider.onReceive(AppWidgetProvider.java:66)
E/loadInstances(26904): at android.app.ActivityThread.handleReceiver(ActivityThread.java:2639)
E/loadInstances(26904): at android.app.ActivityThread.access$1700(ActivityThread.java:155)
E/loadInstances(26904): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1394)

I use that widget https://f-droid.org/packages/com.plusonelabs.calendar/ but this error occured before the import processing was started and might be completely unrelated.