Sometimes after an update, Android still tries to use the old, no longer existing version of the app to update the widgets. Symptoms include empty widgets, empty grid/month widget with two configuration buttons and non reacting buttons.
This is almost impossible to reproduce as it only happens once in ~20 times in testing, but we've managed to trigger it once (on an Xperia Z, stock launcher) and solved it with the following workaround:
- On any home screen, add a DigiCal widget. It does not matter which, just add it and press save in the configuration page.
- All the previous widgets will now be updated again.
Please try the above workaround on your device first.
Other possible workarounds include:
- Restarting the launcher
- Restarting the device
Fixes that shouldn't fail, but require more configuration include
- Removing and recreating the widgets (requires reconfiguration of widgets)
- Uninstalling and installing DigiCal again (this resets all configuration and removes all widgets)
When you've tried any of the workarounds and fixes, please let us know if it worked so we can adjust our answer based on results.