I logged into my nano wallet and it says under accounts nothing to show. I had quite a bit in there and have no idea what could of happened?
Try choosing another node.
Had the same problem today, kinda scared me but changing node fixes it indeed.
Many Supernodes going offline last few days to make required update to NEM Beta 0.6.87. Long time NEM contributor @kodtycoon has created a Supernode status notification service to address exactly this situation.
Full details here Nem Chain Tx & Supernode Notifications Telegram Bot