My iCal just totally went on the fritz. Please help me restore it.

Question

After years of use, all of a sudden my iCal went on the fritz today. Tools would appear and disappear and could not be selected (eg. Month, Week, Day); the to-do list disappeared; calendars in the list of calendars at the top left would appear and disappear and could not be selected; I could not add a new event. The monthly calendar at the bottom left would appear and disappear but fortunately I would allow me to move to a different week so that I could view the events in my calendar, but not move, change, delete, or add events. I could not export.
Apparently the problem is in my user files. I created a new computer account, logged into that account, and iCal worked fine there.
I am using iCal 3.0.8 and OS X 10.5.8.
I tried trashing Home/Library/Caches, and also all the caches in Home/Library/Calendars/ , and also Home/Library/Preferences/com.apple.ical (all of them). Upon restart, the problems are still there.
I do not have a backup of iCal files per se. I do have a Time Machine backup of my computer files. I tried bringing back a previous version of all the files in Home/Library/Calendars, but that did not work.
I guess I need somehow to clean up the base iCal file. Frankly, I don't know where that is. I thought that the Home/Library/Calendars/ folder was the place that iCal used, since it has a folder for each calendar with an info.plist file on the particular calendar's name, color, etc., and then an enclosed folder with a file for each event and to-do item for that particular calendar. However, it appears that this is not true and there must be some other master file location, which just populates the Home/Library/Calendars folder for convenience. For example, when I created a new account on my computer and ran iCal, if I created calendars and events in the program, and then quit the program and deleted a calendar from the Home/Library/Calendars folder or deleted a particular event from the Events folder inside the Home/Library/Calendars calendar folder, I found that when I restarted iCal, it still had the calendar and event, and recreated them inside the Home/Library/Calendars folder. Similarly, if I added to the Home/Library/Calendars folder on the new computer account one of the folders for a calendar and events I have from my existing account, they do not appear when running iCal. Thus, there must be some other place where the data for the iCal program resides.
I would desperately like to get the program working again, with all my data intact. Is there some way that I can "clean" the base file, and bring in the data again. If not, what files do I need to bring back from TimeMachine to restore iCal to its condition from an earlier time when it was working? I know that it is not enough to just bring in the files from Home/Library/Calendars.
Any help would be greatly appreciated.

Answer 1

Dear John,
Thank you again for your thoughts and help.
I tried restoring from the backup created earlier, but that did not work. Apparently, the backup is also corrupted. When I did a restore, iCal just hung. It appears that the data was imported, but then something prevented it from finishing. When I restarted iCal, I now had double entries for each event, and the same problems with the program not working.
However, after many troubleshooting attempts, I have finally got the program working and restored data from TimeMachine from a week ago. Here is what I learned. (Please give me the benefit of your thoughts on all of this):
There apparently is some file (probably associated with iSync) that stores all of the data in iCal. It may be the case that there is one file which stores the calendars, and a separate one which stores the events for those calendars. The data is also found in the Home/Library/Calendars folder. It appears that on system startup (without even starting iCal), if the system does not detect the Calendars folder, it creates a new one, and populates it with default "Home" and "Work" calendars with no items in them. However, the system then goes on to check the background database (iSync?) and if there is calendar data there, it adds those calendars and the events in those calendars to the Calendars folder. (Therefore, the data in the database is in some location other than the Calendars folder, because even when everything is deleted from the Calendars folder, trashed and emptied, the system recreates all of the data, repopulates the Calendars folder with the data, and it appears in iCal.) Thus, it appears that if there is no Calendars folder initially, the system does two things on startup (or other sync event): (1) create "Home" and "Work" calendars, and (2) import all other calendars and their associated events from the sync database into the Calendars folder and make it available to iCal.
If changes are made in iCal to add events, etc., but the info in the Calendars folder is deleted before a system restart (or other sync event), on a restart with a blank Calendars folder, the new Calendars folder is repopulated with the calendars and events from the database, but does not include the new events. On the other hand, if changes are made in iCal to add events, etc., and the Calendars folder is then left alone through a restart, it appears that on the shut down there is another syncing that takes place--this time the new data added by iCal to the Calendars folder is now added to the database. Thus, after the restart, if you delete the Calendars folder, and restart again, the system recreates the Calendars folder, and the added events are now there.
If I create a new user account, and replace the Calendars folder with a copy of the Calendars folder from my existing account, and then restart, the system again compares the Calendars folder with the database (blank). Since the database started with no information, it creates a "Home" and "Work" calendar in the Calendars folder. However, it also adds the calendars and entries that are in the Calendars folder to the database. I know it is now there because if I delete, trash, and empty the Calendars folder, and restart the computer, the Calendars folder is now repopulated with all of the data from the database.
So, as best I can tell, on system startup (or other sync event?), the system compares the database and the Calendars folder. If there is nothing in the Calendars folder, the system creates "Home" and "Work" calendars. If there are other calendars in the database, and they are not in the Calendars folder, the system creates the calendars and their events in the Calendars folder from the database and they are now available to iCal. When using iCal, changes that are made, such as adding or deleting events or calendars, are reflected by immediate changes to the files and folders in the Calendars folder. However, it appears that the database is not changed immediately, at least with regard to added or deleted events. (I am not sure whether adding or deleting a calendar affects the database immediately or not.) On system shutdown (or other sync event), the system again compares the database and the Calendars folder, and updates the database with the changes made to the Calendars folder.
What I think happened in my case is that somehow the database lost the identity of my calendars. It had the events (in their proper colors), but did not have the calendars themselves. This caused iCal to freak out. When I removed the Calendars folder and started over, the system created "Home" and "Work" calendars (and "Birthdays" subscription calendar), and then brought back in all the old events again from the database. On running iCal, there were "Home", "Work" and "Birthdays" calendars in the calendar list, but none of the names of the other calendars. However, all the events were still there. This again caused iCal to freak out.
When I tried restoring the iCal backup file, apparently the same corruption problem existed in the backup file. So it added all the events in again without a calendar reference (although in the correct colors), but never cleaned up -- since the restore never finished--it just hung. The result was that iCal now had two copies of each event, but still was not working because all of those events were somehow not properly associated to a calendar.
I then tried deleting the Calendars folder and resetting iSync. That worked wonders. Resetting iSync apparently cleaned out all of the events from the database. However, it did not clean out the seven calendars I had before. Rather, it now made them able to be recognized by iCal. When I then ran iCal, all of the calendars I had before showed up in iCal, but there were no events in them. (That is why I think there is one database file which identifies the calendars that the user is currently using, and a separate database file which stores the events. Resetting iSync cleans out the events database, but does not change the list of calendars that the user is currently using.)
Having apparently cleared the database of its problems, I then tried restoring with the backup file again. Unfortunately, that did not work. It really appears that the backup file is corrupted. The restore only brought back the same problem-- the events were brought back without any associated calendars, and iCal did not work.
So, I reset iSync again to clean out the database, trashed the Calendars folder, used TimeMachine to bring back a former copy of my Calendars folder, and restarted. I ran iCal and it recognizes all of the calendars and the events that were in them. I restarted again. (That apparently updated the database.) I deleted the Calendars folder. I restarted again. The system now recreated the Calendars folder from the database--adding a "Home" and "Work" calendar.
So, I think there is a two-way synchronization between the database and the Calendars folder.
Ultimately, the resolution to my problem would be:
(1) reset iSync to clear the database
(2) delete the Calendars folder
(3) restore a previous version of the Calendars folder from TimeMachine
(4) restart
(5) iCal runs fine, using the data brought back from TimeMachine
(6) restart again to sync the data to the database.