This happened to me too. I opened a note from yesterday in Mac client, typed in about 30 characters, and then saw a few moments later (perhaps after sync) that most of my note was gone. Evernote 6.0.8 on OS X 10.10.3 (Yosemite latest). iOS 7.7.1 client on iPhone renders same note fine so appears to be a problem in the Mac client. If a bad character was injected, it would also have been injected by the Mac client. The posts say to go to support link in gazumped's signature, but it lists only a link for BOINC. If details are provided as to where to best submit, I will probably submit later today. Perhaps the normal support link submit bug/crash/suggestion for Premium users? It wouldn't help non-Premium. Possibly this arose from network corruption of byte values, but with some simple hash computations and retry-on-hash-fail the odds against that would be incredible. (Run MD5 or SHA2 and they would be 1 in 2^128 or 2^160 respectively. Run them both and I estimate odds are lower than 2^200 = 10^60 which are sufficiently low odds that cryptographers consider them impossible in practice last I heard. These particular hashes may be too slow and therefore too expensive for large notes since a modern CPU can only do hundreds of megabytes per second, but could at least be used for text notes and there might be something more powerful than the current one that can could still be used for binary notes. Doing it on large notes could be another service for Premium users.) In my case I was able to resurrect from Note History and then remake my change, since it was recent and short enough I could replicate it from memory.