Guys did you tried to install the lower version of electrum
http://download.electrum.org/ i suggest try to install electrum 2.9.3 and maybe it can recognize your ledger nano
if still not i don't see any solution yet about this issue but my guess its a driver issue that is why its not detected by electrum..
Did you tried to change the usb maybe your usb was damaged that is why it can't recognize also try it in other OS instead try windows os if its working fine maybe your ubuntu os had problem to recognized your hardware wallet.. just like other ledger nano users experienced.
