I've created issue log in git : https://github.com/NodeBB/NodeBB/issues/8829

try CWP webpanel they have all what you need including email server

@baris said in Upgrade from version 1.14.x to 1.15.x got error:

Upgrading these two dependencies should fix this error

"@nodebb/mubsub": "1.7.1",
"@nodebb/socket.io-adapter-mongo": "3.1.1",

thanks solved.