I've received a number of Event invitations lately and they appear in my Outlook 2011 (14.4.49) but I cannot open them to view the details etc.

If I double click to open them like I normally would nothing happens.

I checked the Console application and found the following each time I tried to open one of these - anyone else experiencing this or know of a solution?

I'm using Outlook with Exchange Server if that helps. 

22/04/2015 11:46:36.539 am Microsoft Outlook[956]: [<ECCalendarEventTimeZone 0x7c6103e0> valueForUndefinedKey:]: this class is not key value coding-compliant for the key yesterdayTomorrowOrNothing.
22/04/2015 11:46:36.540 am Microsoft Outlook[956]: (
0   CoreFoundation                      0x9adb7471 __raiseError + 193
1   libobjc.A.dylib                     0x96810091 objc_exception_throw + 162
2   CoreFoundation                      0x9adb7061 -[NSException raise] + 17
3   Foundation                          0x96adb4d3 -[NSObject(NSKeyValueCoding) valueForUndefinedKey:] + 282
4   Foundation                          0x969dc7c6 _NSGetUsingKeyValueGetter + 52
5   Foundation                          0x969dc78a -[NSObject(NSKeyValueCoding) valueForKey:] + 406
6   ObjCOPF                             0x02d9b4f3 GetOPFContextOfCurrentThread + 11159
7   Foundation                          0x969f6305 -[NSObject(NSKeyValueCoding) valueForKeyPath:] + 444
8   Microsoft Outlook                   0x005931a1 _ZNSt6vectorISsSaISsEE13_M_insert_auxEN9__gnu_cxx17__normal_iteratorIPSsS1_EERKSs + 175813
9   Microsoft Outlook                   0x001630b9 _ZNSt8_Rb_treeImSt4pairIKmxESt10_Select1stIS2_ESt4lessImESaIS2_EE8_M_eraseEPSt13_Rb_tree_nodeIS2_E + 24979
10  Microsoft Outlook                   0x001597f4 _ZNSt8_Rb_treeImmSt9_IdentityImESt4lessImESaImEE8_M_eraseEPSt13_Rb_tree_nodeImE + 9044
11  Microsoft Outlook                   0x00159460 _ZNSt8_Rb_treeImmSt9_IdentityImESt4lessImESaImEE8_M_eraseEPSt13_Rb_tree_nodeImE + 8128
12  Microsoft Outlook                   0x005a1e13 _ZNSt6vectorISsSaISsEE13_M_insert_auxEN9__gnu_cxx17__normal_iteratorIPSsS1_EERKSs + 236343
13  Foundation                          0x96a1dc31 _NSSetObjectValueAndNotify + 285
14  Microsoft Outlook                   0x00158512 _ZNSt8_Rb_treeImmSt9_IdentityImESt4lessImESaImEE8_M_eraseEPSt13_Rb_tree_nodeImE + 4210
15  Microsoft Outlook                   0x001581f0 _ZNSt8_Rb_treeImmSt9_IdentityImESt4lessImESaImEE8_M_eraseEPSt13_Rb_tree_nodeImE + 3408
16  Microsoft Outlook                   0x00158171 _ZNSt8_Rb_treeImmSt9_IdentityImESt4lessImESaImEE8_M_eraseEPSt13_Rb_tree_nodeImE + 3281
17  Foundation                          0x96a159cb __NSFireTimer + 117
18  CoreFoundation                      0x9ad10ea6 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 22
19  CoreFoundation                      0x9ad10863 __CFRunLoopDoTimer + 1395
20  CoreFoundation                      0x9ad8b06d __CFRunLoopDoTimers + 349
21  CoreFoundation                      0x9acc8353 __CFRunLoopRun + 1779
22  CoreFoundation                      0x9acc79ea CFRunLoopRunSpecific + 394
23  CoreFoundation                      0x9acc784b CFRunLoopRunInMode + 123
24  HIToolbox                           0x997abb5d RunCurrentEventLoopInMode + 259
25  HIToolbox                           0x997ab8e2 ReceiveNextEventCommon + 526
26  HIToolbox                           0x997ab6bd _BlockUntilNextEventMatchingListInModeWithFilter + 92
27  AppKit                              0x9aedf349 _DPSNextEvent + 1602
28  AppKit                              0x9aede870 -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 119
29  AppKit                              0x9aed115c -[NSApplication run] + 727
30  AppKit                              0x9aeb9ff8 NSApplicationMain + 1165
31  Microsoft Outlook                   0x000d6a9e _ZN12CSharablePtrI14CNetHostOptionE3SetEPS0_ + 480
)
22/04/2015 11:46:37.448 am Microsoft Outlook[956]: [<ECCalendarEventTimeZone 0x7d54eac0> valueForUndefinedKey:]: this class is not key value coding-compliant for the key yesterdayTomorrowOrNothing.
22/04/2015 11:46:37.451 am Microsoft Outlook[956]: (
0   CoreFoundation                      0x9adb7471 __raiseError + 193
1   libobjc.A.dylib                     0x96810091 objc_exception_throw + 162
2   CoreFoundation                      0x9adb7061 -[NSException raise] + 17
3   Foundation                          0x96adb4d3 -[NSObject(NSKeyValueCoding) valueForUndefinedKey:] + 282
4   Foundation                          0x969dc7c6 _NSGetUsingKeyValueGetter + 52
5   Foundation                          0x969dc78a -[NSObject(NSKeyValueCoding) valueForKey:] + 406
6   ObjCOPF                             0x02d9b4f3 GetOPFContextOfCurrentThread + 11159
7   Foundation                          0x969f6305 -[NSObject(NSKeyValueCoding) valueForKeyPath:] + 444
8   Microsoft Outlook                   0x005931a1 _ZNSt6vectorISsSaISsEE13_M_insert_auxEN9__gnu_cxx17__normal_iteratorIPSsS1_EERKSs + 175813
9   Microsoft Outlook                   0x001630b9 _ZNSt8_Rb_treeImSt4pairIKmxESt10_Select1stIS2_ESt4lessImESaIS2_EE8_M_eraseEPSt13_Rb_tree_nodeIS2_E + 24979
10  Foundation                          0x969f65b2 _NSSetUsingKeyValueSetter + 67
11  Foundation                          0x969f6567 -[NSObject(NSKeyValueCoding) setValue:forKey:] + 417
12  AppKit                              0x9af774f4 -[NSObjectParameterBinder _updateObject:observedController:observedKeyPath:context:] + 1326
13  AppKit                              0x9af76fbf -[NSObjectParameterBinder _observeValueForKeyPath:ofObject:context:] + 78
14  AppKit                              0x9af76ebe -[NSBinder observeValueForKeyPath:ofObject:change:context:] + 566
15  AppKit                              0x9af76c83 -[NSBinder _performConnectionEstablishedRefresh] + 82
16  AppKit                              0x9af7506c -[NSBinder establishConnection] + 359
17  AppKit                              0x9af6d22f -[NSObject(NSKeyValueBindingCreation) bind:toObject:withKeyPath:options:] + 706
18  Microsoft Outlook                   0x001638fb _ZNSt8_Rb_treeImSt4pairIKmxESt10_Select1stIS2_ESt4lessImESaIS2_EE8_M_eraseEPSt13_Rb_tree_nodeIS2_E + 27093
19  Microsoft Outlook                   0x005a218e _ZNSt6vectorISsSaISsEE13_M_insert_auxEN9__gnu_cxx17__normal_iteratorIPSsS1_EERKSs + 237234
20  AppKit                              0x9aecbe59 -[NSIBObjectData nibInstantiateWithOwner:topLevelObjects:] + 1253
21  AppKit                              0x9af78760 -[NSNib _instantiateNibWithExternalNameTable:] + 631
22  AppKit                              0x9b0acb80 -[NSNib instantiateNibWithOwner:topLevelObjects:] + 267
23  AppKit                              0x9b0ac901 -[NSViewController loadView] + 211
24  OfficeWindowLocalizer               0x02ae3145 MSGetMBUNamedString + 9129
25  Microsoft Outlook                   0x001142c1 _ZN12CSharablePtrI15CScheduleRecordE3SetEPS0_ + 55949
26  AppKit                              0x9afd4a34 -[NSViewController view] + 42
27  Microsoft Outlook                   0x001141c2 _ZN12CSharablePtrI15CScheduleRecordE3SetEPS0_ + 55694
28  Microsoft Outlook                   0x0054c461 _ZN12CSharablePtrI17CCommonMailServerE3SetEPS0_ + 116633
29  AppKit                              0x9aecbe59 -[NSIBObjectData nibInstantiateWithOwner:topLevelObjects:] + 1253
30  AppKit                              0x9aebf975 loadNib + 369
31  AppKit                              0x9aebeda1 +[NSBundle(NSNibLoading) _loadNibFile:nameTable:withZone:ownerBundle:] + 320
32  AppKit                              0x9b16897e +[NSBundle(NSNibLoading) loadNibFile:externalNameTable:withZone:] + 154
33  AppKit                              0x9b168789 -[NSWindowController loadWindow] + 231
34  OfficeWindowLocalizer               0x02ae0a78 OfficeWindowLocalizer + 6776
35  AppKit                              0x9b16d943 -[NSWindowController window] + 81
36  Microsoft Outlook                   0x0054c368 _ZN12CSharablePtrI17CCommonMailServerE3SetEPS0_ + 116384
37  Microsoft Outlook                   0x004faf6b _ZN12CSharablePtrI14CDNSConnectionE3SetEPS0_ + 112547
38  Microsoft Outlook                   0x004fb658 _ZN12CSharablePtrI14CDNSConnectionE3SetEPS0_ + 114320
39  Microsoft Outlook                   0x0054b837 _ZN12CSharablePtrI17CCommonMailServerE3SetEPS0_ + 113519
40  Microsoft Outlook                   0x0075a4d5 _ZN2CF18DictionaryGetValueINS_4DateEEENS_6TraitsIT_E3PtrENSt3tr110shared_ptrIK14__CFDictionaryEEPKv + 60779
41  libobjc.A.dylib                     0x9681c262 -[NSObject performSelector:] + 62
42  CoreFoundation                      0x9ac8db9d __invoking___ + 29
43  CoreFoundation                      0x9ac8da6b -[NSInvocation invoke] + 315
44  CoreFoundation                      0x9ad3a94a -[NSInvocation invokeWithTarget:] + 74
45  CoreFoundation                      0x9ad072f9 ___forwarding___ + 457
46  CoreFoundation                      0x9ad0710e _CF_forwarding_prep_0 + 14
47  libobjc.A.dylib                     0x9681c2af -[NSObject performSelector:withObject:] + 70
48  AppKit                              0x9b10b8a5 -[NSApplication sendAction:to:from:] + 438
49  Microsoft Outlook                   0x006be8e9 _ZN12CSharablePtrI25CSignatureProtocolAdaptorE3SetEPS0_ + 214107
50  AppKit                              0x9b0f0a9d -[NSWindow sendEvent:] + 11953
51  OutlookPaletteItems                 0x02ebab35 getCIDsInDOMRangeInWebview + 16257
52  Microsoft Outlook                   0x00191fb8 _ZNSt4listI12CSharablePtrI14CNetHostOptionESaIS2_EE6removeERKS2_ + 9036
53  AppKit                              0x9b08c91d -[NSApplication sendEvent:] + 4034
54  Microsoft Outlook                   0x00133e3d _ZN3OPF12CopyPropertyI26OpaqueSavedSpotlightSearchEElP13OpaqueContextPKT_N16PropertyAccessorI14CUnicodeStringNS_6TraitsIS4_E12SharableTypeEE7GetPropEPKcPPK10__CFString + 107843
55  AppKit                              0x9aed11bc -[NSApplication run] + 823
56  AppKit                              0x9aeb9ff8 NSApplicationMain + 1165
57  Microsoft Outlook                   0x000d6a9e _ZN12CSharablePtrI14CNetHostOptionE3SetEPS0_ + 480
)