We tried to remove as many errors as we could. But it is not a 100%. Sometimes an error occurs and that isn't handled. The will result in a catch-all mechanism and you will see an pop-up message like this:
The first sentence is the error that actually occured. In this case 'Object reference is Nil'. You can continue or abort. If you continue it says you can risk data corruption. This is seldom the case and you have an automatic backup so you could continue. However the application may not behave as it should. But it would be very useful if you send this error to us so that it can be fixed. You can use the contact form. Please describe the situation and the error message. The version number of the application is needed too so we can try to simulate it. This can be found in the application through the 'About' menu.