@julian yes, I'm using version 0.9.3.

@pichalite said:

npm ls connect-mongo

I started the instalation from scratch, now using the answer from:
https://community.nodebb.org/topic/7302/fatal-error-nan-h-no-such-file-or-directory
after npm start and database configuration I received the message:

make: Entering directory /root/nodebb/node_modules/mongodb/node_modules/kerberos/build' CXX(target) Release/obj.target/kerberos/lib/kerberos.o In file included from ../lib/kerberos.cc:1:0: ../lib/kerberos.h:5:27: fatal error: gssapi/gssapi.h: No such file or directory #include <gssapi/gssapi.h> ^ compilation terminated. make: *** [Release/obj.target/kerberos/lib/kerberos.o] Error 1 make: Leaving directory /root/nodebb/node_modules/mongodb/node_modules/kerberos/build'
gyp ERR! build error
gyp ERR! stack Error: make failed with exit code: 2
gyp ERR! stack at ChildProcess.onExit (/root/nodebb/node_modules/npm/node_modules/node-gyp/lib/build.js:276:23)
gyp ERR! stack at emitTwo (events.js:87:13)
gyp ERR! stack at ChildProcess.emit (events.js:172:7)
gyp ERR! stack at Process.ChildProcess._handle.onexit (internal/child_process.js:200:12)
gyp ERR! System Linux 3.13.0-71-generic
gyp ERR! command "/usr/bin/nodejs" "/root/nodebb/node_modules/npm/node_modules/node-gyp/bin/node-gyp.js" "rebuild"
gyp ERR! cwd /root/nodebb/node_modules/mongodb/node_modules/kerberos
gyp ERR! node -v v4.2.3
gyp ERR! node-gyp -v v3.2.1
gyp ERR! not ok
connect-mongo@0.8.2 node_modules/connect-mongo

so I ran: sudo apt-get install libkrb5-dev and finally ./nodebb start

Now everything worked like a charm.

Thx.

@pichalite yes I'm using the tutorial located at: https://docs.nodebb.org/en/latest/installing/os/ubuntu.html.
$ sudo apt-get install -y git nodejs mongodb build-essential.
When I use redis everything works well.
thx

Thanks you Julian,

It worked. I deleted utf-8-validate and bufferutil section from npm-shrinkwrap.json and after
npm install --production, everithing gone well.

21/12 15:11 [18704] - error: Unable to initialize MongoDB! Is MongoDB installed? Error :Use of const in strict mode.
21/12 15:11 [18704] - warn: NodeBB Setup Aborted.
SyntaxError: Use of const in strict mode.
at Module._compile (module.js:439:25)
at Object.Module._extensions..js (module.js:474:10)
at Module.load (module.js:356:32)
at Function.Module._load (module.js:312:12)
at Module.require (module.js:364:17)
at require (module.js:380:17)
at Object.<anonymous> (/root/nodebb/node_modules/connect-mongo/index.js:1:80)
at Module._compile (module.js:456:26)
at Object.Module._extensions..js (module.js:474:10)
at Module.load (module.js:356:32)

I need help. I'm trying to install a fresh copy of nodebb and I'm getting this error:

I've done the same procedure last week and the installation worked fine.

make: Entering directory /root/nodebb/node_modules/utf-8-validate/build' CXX(target) Release/obj.target/validation/src/validation.o ../src/validation.cc:15:17: fatal error: nan.h: No such file or directory #include "nan.h" ^ compilation terminated. make: *** [Release/obj.target/validation/src/validation.o] Error 1 make: Leaving directory /root/nodebb/node_modules/utf-8-validate/build'
gyp ERR! build error
gyp ERR! stack Error: make failed with exit code: 2
gyp ERR! stack at ChildProcess.onExit (/usr/lib/node_modules/npm/node_modules/node-gyp/lib/build.js:270:23)
gyp ERR! stack at emitTwo (events.js:87:13)
gyp ERR! stack at ChildProcess.emit (events.js:172:7)
gyp ERR! stack at Process.ChildProcess._handle.onexit (internal/child_process.js:200:12)
gyp ERR! System Linux 3.13.0-71-generic
gyp ERR! command "/usr/bin/nodejs" "/usr/lib/node_modules/npm/node_modules/node-gyp/bin/node-gyp.js" "rebuild"
gyp ERR! cwd /root/nodebb/node_modules/utf-8-validate
gyp ERR! node -v v4.2.3
gyp ERR! node-gyp -v v3.0.3
gyp ERR! not ok

Thanks in advance