That's an odd one. So what's happening is that for every profile, there's a keychain which holds all the keys that decrypt your data (boards and notes mainly). On top of that, each note that is in a board holds it's own key in its own data, encrypted with that board's key. So if you have the key of a board you can essentially decrypt any note in that board.
When the note is being decrypted, the app does an extensive search for keys that can decrypt the note. This search is failing and it's holding up the profile from loading. Since the note has an old id, I'm guessing that, unless you edited it before you started getting the error, it doesn't have a keychain entry (only boards got keychain entries in the previous version). That means that the note is trying to decrypt itself using the board's key and is failing.
The only board the note is in is the board with id 5509bd352b13750765000388, which doesn't appear to be present in the database.
I'm guessing the board was removed (please correct me if I'm wrong), but because the notes don't have keychain entries (they only get one when edited), they all became un-decryptable (there's no way left to retrieve their key).
There are two ways to fix:
1. I can go get a database backup and restore board 5509bd352b13750765000388 to your profile, which will allow those notes to be read again.
2. I can clear out all the notes in board 5509bd352b13750765000388 (looks like 12 of them) from the database to get your profile loading again (assuming you don't care about them).
Then there's the real fix for me which is to make sure all notes that don't have a keychain entry for their key create one when the profile loads the first time. Then you could remove boards all day and the notes will still load.