Here's my situation: I primarily use the EN app on my MacBook. Last night (and throughout the day today), I've made several additions to existing notes, hit sync, and received the failure message that JMichael displays above. However, when I check the EN app on my phone, I have all of the updates to my notes. Same when I check my EN account via the web service. So, the MacBook app continues to inform me that syncing has failed (which also prevents me from using the Note Link functionality), but syncing does appear to be taking place. Odd.