Hi, I've got the latest stable build of the CS running on Snow leopard with iCal and iPhone clients. I keep getting the following error message to which I simply choose the option 'Go Online' in the dialog box and it goes away and everything is fine. The server responded with “HTTP/1.1 500 Internal Server Error” to operation CalDAVAccountRefreshQueueableOperation. The Console log shows the following iCal error 12/1/09 12:41:36 PM iCal[994] CalDAV CalDAVAccountRefreshQueueableOperation failed: status 'HTTP/1.1 500 Internal Server Error' request: <?xml version="1.0" encoding="utf-8"?> <x0:propfind xmlns:x0="DAV:" xmlns:x3="http://apple.com/ns/ical/" xmlns:x1="http://calendarserver.org/ns/" xmlns:x2="urn:ietf:params:xml:ns:caldav"> <x0:prop> <x1:xmpp-server/> <x1:xmpp-uri/> <x1:getctag/> <x0:displayname/> <x2:calendar-description/> <x3:calendar-color/> <x3:calendar-order/> <x2:supported-calendar-component-set/> <x0:resourcetype/> <x2:calendar-free-busy-set/> <x2:schedule-calendar-transp/> <x2:schedule-default-calendar-URL/> <x0:quota-available-bytes/> <x0:quota-used-bytes/> <x2:calendar-timezone/> <x0:current-user-privilege-set/> </x0:prop> </x0:propfind> ... response: HTTP/1.1 500 Internal Server Error Date: Tue, 01 Dec 2009 20:41:36 GMT Content-Length: 201 Content-Type: text/html Server: Twisted/8.2.0 TwistedWeb/8.2.0 <html><head><title>Internal Server Error</title></head><body><h1>Internal Server Error</h1>An error occurred rendering the requested page. More information is available in the server log.</body></html> and the server error log shows 2009-12-01 12:41:35-0800 [-] [caldav-1] [-] [twistedcaldav.directory.principal#error] No principal found for UID: 0f63c916-ac38-5249-a629-f3b13f9c0dff 2009-12-01 12:41:35-0800 [-] [caldav-1] [-] Exception rendering: 2009-12-01 12:41:36-0800 [-] [caldav-1] [-] Unhandled Error 2009-12-01 12:41:36-0800 [-] [caldav-1] Traceback (most recent call last): 2009-12-01 12:41:36-0800 [-] [caldav-1] File "Library/Python/2.6/site-packages/twisted/internet/defer.py", line 832, in unwindGenerator 2009-12-01 12:41:36-0800 [-] [caldav-1] return _inlineCallbacks(None, f(*args, **kwargs), Deferred()) 2009-12-01 12:41:36-0800 [-] [caldav-1] File "Library/Python/2.6/site-packages/twisted/internet/defer.py", line 749, in _inlineCallbacks 2009-12-01 12:41:36-0800 [-] [caldav-1] result = g.send(result) 2009-12-01 12:41:36-0800 [-] [caldav-1] File "Library/Python/2.6/site-packages/twistedcaldav/resource.py", line 341, in accessControlList 2009-12-01 12:41:36-0800 [-] [caldav-1] acls = (yield super(CalDAVResource, self).accessControlList(request, *args, **kwargs)) 2009-12-01 12:41:36-0800 [-] [caldav-1] File "Library/Python/2.6/site-packages/twisted/internet/defer.py", line 700, in unwindGenerator 2009-12-01 12:41:36-0800 [-] [caldav-1] return _deferGenerator(f(*args, **kwargs), Deferred()) 2009-12-01 12:41:36-0800 [-] [caldav-1] --- <exception caught here> --- 2009-12-01 12:41:36-0800 [-] [caldav-1] File "Library/Python/2.6/site-packages/twisted/internet/defer.py", line 603, in _deferGenerator 2009-12-01 12:41:36-0800 [-] [caldav-1] result = g.next() 2009-12-01 12:41:36-0800 [-] [caldav-1] File "Library/Python/2.6/site-packages/twisted/web2/dav/resource.py", line 1111, in accessControlList 2009-12-01 12:41:36-0800 [-] [caldav-1] acl = self.defaultAccessControlList() 2009-12-01 12:41:36-0800 [-] [caldav-1] File "Library/Python/2.6/site-packages/twistedcaldav/schedule.py", line 248, in defaultAccessControlList 2009-12-01 12:41:36-0800 [-] [caldav-1] davxml.Principal(davxml.HRef(joinURL(myPrincipal.principalURL(), "calendar-proxy-write"))), 2009-12-01 12:41:36-0800 [-] [caldav-1] exceptions.AttributeError: 'NoneType' object has no attribute 'principalURL' 2009-12-01 12:41:36-0800 [-] [caldav-1] 2009-12-01 12:41:36-0800 [-] [caldav-1] [-] [twistedcaldav.accesslog#info] logGlobalHit() only works with an AMP Protocol I don't know where the UID 0f63c916-ac38-5249-a629-f3b13f9c0dff comes from. Any idea about this error? Its simply annoying to have to basically hit OK every couple of hours. Thanks, Scott Buchanan