After some years I was checking my wallets today and found that nanowallet has shut down.
I tried to get into my wallet, but nothing is working...
Does anybody outh there how I can retrieve my XEM-coins?
I would suggest reading the notices at the top of http://nanowallet.io/ and see if the suggestions made there help you sort things out yourself. If you are unable to, reach out to their team using the support address listed near the bottom of their home page.