Notes app broke on Mac Pro after macOS Sierra upgrade I upgraded to macOS Sierra and my Notes app crashes as soon as its launched.

Has anyone else faced this issue?

Crashed Thread:        13  Dispatch queue: NSManagedObjectContext 0x6080001c41a0

Exception Type:        EXC_CRASH (SIGABRT)
Exception Codes:       0x0000000000000000, 0x0000000000000000
Exception Note:        EXC_CORPSE_NOTIFY

Application Specific Information:
*** Terminating app due to uncaught exception 'CKException', reason: 'data can not be nil'
abort() called
terminating with uncaught exception of type CKException

Application Specific Backtrace 1:
0   CoreFoundation                      0x00007fff9adb052b __exceptionPreprocess + 171
1   libobjc.A.dylib                     0x00007fffaf488cad objc_exception_throw + 48
2   CloudKit                            0x00007fff9a6d71d0 -[CKEncryptedData initWithEncryptedData:] + 0
3   CloudKit                            0x00007fff9a6d747b -[CKEncryptedData copyWithZone:] + 92
4   CloudKit                            0x00007fff9a6976cc -[CKRecord copyWithZone:] + 1706
5   NotesShared                         0x00007fffaa6ede18 -[ICCloudSyncingObject newlyCreatedRecord] + 75
6   NotesShared                         0x00007fffaa803ce0 -[ICNote(CloudKit) newlyCreatedRecord] + 65
7   NotesShared                         0x00007fffaa6be0aa +[ICCloudContext deduplicatedRecordsForCloudObjects:] + 703
8   NotesShared                         0x00007fffaa6b8e76 -[ICCloudContext operationsToModifyRecordsForCloudObjectsToSave:delete:deleteShares:saveUserSpecificRecords:addDependencies:] + 1037
9   NotesShared                         0x00007fffaa6c2208 -[ICCloudContext _processCloudObjects:completionHandler:] + 1914
10  NotesShared                         0x00007fffaa6c19fd __53-[ICCloudContext processObjectIDs:completionHandler:]_block_invoke
I'm not sure currently, but basically some text/special symbols is to blame.
As stated here: http://forums.macrumors.com/threads/notes-crashing-in-macos-sierra.2000203/

Katalyst2 said: ↑
Me too -- mid-2013 MBA 13. Damn annoying!
EDIT: And as usual, as soon as I post a problem report, I somehow manage to fix it :)
What I just did now was log into iCloud.com and I made a tiny edit to one of my notes (in my case, I deleted one line on a to-do list). Then I waited a few seconds for the data to refresh, and then I tried opening Notes locally again.
Let us know if this works.