The calendar is empty on iOS6

When running Week Calendar for the first time on IOS6, your calendar might appear empty after tapping on OK on the following screen:

How to resolve this?

There are multiple methods to resolve this: Once your events are displayed again, this issue will not show up anymore.

Another solution (still no events)

If you denied Week Calendar access to your events, it can't show events of course.
To restore access, please read the following guide.

Why does this happen?

Due to changes made by Apple in iOS6, calendar apps get an empty list of events from the iOS operating system on first start.
Week Calendar 5.0.3 will resolve this and is currently awaiting approval by Apple's review team.