ical: The server responded "HTTP/1.1 403 Forbidden"

I had the same problem after MobileMe update!!
It seems to affect just the calendar with a lot of events o tasks.
May hearings calendar use to have 1500 events and 1250 tasks.
Has Anyone news about that?

Same issue began today with invites from my wife's account. Tried deleting her shared calendar and my prefs. All to no avail. Frustrated...

I'm also having this problem with my MobileMe account when refreshing or creating new items. Only appears to have started in the last few days.

I've tried everything: erase all sync data; delete all previous calendar; create a new account on MobileMe; create a new account on Mac!
Nothinhg!!
It seems to a be a very big bug!
Anybody from Apple can help us?

ok Guys!
l'et's try this http://www.busymac.com/busycal/index.html
Seems amazing. It cost 49 US $ (with 30 days free trial period, during which you can at least upload data on MobileMe error-free) but if it works i will love it!

Add me to this list. Sooooo frustrating! Happens to all my friends that have upgraded to the caldav.

Add me to the list of people experiencing this behavior.

Ok! I think i got it!
let's download the busysync calendar free trial; then upload your data with it on MobileMe; then (if you really need) revert to the use of iCal.
I suggest instead to buy BusySync that offer many more option of iCal and works properly.
On the website you can find a couple of friendly guide to sync and use it.
Enjoy!

So this has become a major problem for my business and keeping track of meeting invites. So there is no way to revert back to the way it was before?? Guess I will be giving Busycal a try if it the only solution.

I upgraded to the new MobileMe Calendar yesterday, and just spent the better part of a day and a half on chat sessions with MobileMe support trying to fix primarily this but also other server errors. Ultimately, I fixed it myself, and this is how...

First, the assumption is your primary calendar is currently listed under ON MY MAC in iCal. Take this calendar and export it to a safe place for backup. And now, if you have the same calendar under user@me.com (where the pinwheel is probably infinitely spinning), right click on it and delete it. If it is your only calendar under me.com, you won't be able to delete it, so just add a dummy calendar and drag it above your primary (to thus become the "primary" to me.com), then delete the real primary now below it. You can delete the dummy later after you get everything working.

Now, referring to Apple support article TS3397, under "Troubleshooting iCal", execute the steps specified under
"Delete and re-enter your CalDAV settings for MobileMe Calendar on your Mac". In general:

- Delete the CalDAV account in iCal Preferences, and quit iCal
- Execute the specified Terminal commands
- Restart your computer
- Open iCal; The CalDAV me.com section should automatically reappear
- Add a new calendar under me.com
- Import from your backup into this new calendar; the pinwheel beside me.com should begin spinning

In a few moments, or awhile, the "Forbidden" popup will inevitably appear. There might even be multiple popups for the same event. Note the details of the event, then dismiss the popups by clicking on the "Revert to Server" button (important). Then go to that calendar (under me.com), find and take note of that event (you can recreate it later), and DELETE it. Repeat these steps and delete each and every "Forbidden" event.

Eventually, you will delete all the offending events, the sync will complete (pinwheel stops), and you will be done. There might a few popups that say "The calendar https://cal.me.com:8443/principals/users/n.nnnnnn/ could not be accessed. It may be in use by someone else. Try again later.", but just dismiss these by clicking on "Revert to Server". Always select this option and NOT "Go Offline".

In my case, my primary calendar has a few hundred events which go back 3-4 years. I needed to delete only 5 events to get squared away.

Hope this helps.

This is a good workaround, but it cannot be work for people (like me) that have calendar with ten years old entry and, especially, in a lot of entry, long notes describing everything as occurred regarding the event. It will be hard and dangerous to copy all that stuff. Maybe you can copy and paste the entry before delete, but it depends on the number of the events and you might lose some of these.
Anyway if you use the free version of Busycal you will able to upload alla your data to MobileME without error. Then revert to iCal. It seems to be simple.
Thanks

This is one of Apple's worst "upgrades" ever. Both my home and office Mac frequently pop up with a dialog box that says, "The calendar https://cal.me.com:xxx/principals/users/xxx/ could not be accessed. It may be in use by someone else. Try again later." If I click "Go Online," I'm able to connect to the server. But if I'm not sitting at that computer, the dialog box stays open forever until I dismiss it. In the meantime, the calendar on my iPhone and on the other Mac don't refresh. Apple MUST fix this IMMEDIATELY. At a minimum, the dialog box should dismiss itself after a few seconds.

I found this error when I had failed to set up the SRV record in DNS properly for the iCal service.

This link gives a good walk-through:

http://www.nuxnix.com/apple/13-snowleopard/78-ical-server.html

TG

The workaround I posted only gets you past the server errors. Then, you discover events have magically gained 1 and 2 alerts, and in some cases duplicated themselves. Bottom line is the data integrity through the upgrade is poor.

I say poor job by Apple and the MobileMe team on this one.

I should qualify:

If you're getting this error from an iCal service, and not MobileMe, the solution I mentioned will work (you're posting this in the SLS thread, after all).

If this is a wobbly chucked by MobileMe, then I'm afraid the ball's in Apple's court.