Today’s blooper occurs in the Mac calendar program iCal (version 4.0.4 (1395). It occurs when you invite people to a meeting. When you try to close the event editing dialog, the modal dialog below occurs, saying “You’re about to send an invitation for [the event]. Do you want to send [the event] now or continue editing the event?”
The problem is that there is no obvious way to ‘escape’. You have to send to proceed. If you click ‘edit’ you are just taken to the dialog behind where you are editing the event. You can’t close that dialog; if you try to, the “You’re about to …” modal dialog reappears. You can’t quit iCal either without the dialog reappearing. And if you ‘force quit’ iCal, the pesky dialog reappears as soon as iCal starts again!
This might not on the surface appear to be so bad. After all, if you have listed some people to invite, presumably you want to actually invite them. The problem is, this dialog often appears ‘accidentally’. If you touch the event in the daily layout, perhaps dragging it a little by mistake, it thinks it is a ‘revised event’ and all the participants must be informed (although it still asks to 'send an invitation' rather than 'send invitees notice of a change'). If you want to put some comments on the event for you own information, it insists on having you send this to everybody invited.
I have often wanted set up an event in my calendar yet not immediately send the invitations until I am ready to do so. No can do. Invitations must be sent or you are in dialog hell.
There is a workaround: Delete all the invitees. But then you have lost track of everybody you were planning to invite (or everybody you did invite if this is a minor update you don't want to bother telling people about).
Apple needs to fix iCal so you can save a changed event without sending it to the invitees. It could put a graphic flag on the event warning you that you have not completed sending invitations or updates.