Steps to Reproduce
cd ~/MagicMirror
rm -rf ./node_modules
git pull
npm install
npm start
Platform: Raspberry Pi 2 (Arch Linux ARM)
Node Version: 7.5.0
NPM Version: 4.2.0
MagicMirror Version: devel branch (11c0221f8172e9043473d4e42ae5c0cd994b9d59)
Issue:
It is not possible to start the electron magic with latest node/npm versions:
$ npm start
[email protected] start /home/mm/MagicMirror
sh run-start.sh/home/mm/MagicMirror/node_modules/electron/index.js:9
throw new Error('Electron failed to install correctly, please delete node_modules/' + path.basename(__dirname) + ' and try installing again')
^Error: Electron failed to install correctly, please delete node_modules/electron and try installing again
at Object.(/home/mm/MagicMirror/node_modules/electron/index.js:9:9)
at Module._compile (module.js:571:32)
at Object.Module._extensions..js (module.js:580:10)
at Module.load (module.js:488:32)
at tryModuleLoad (module.js:447:12)
at Function.Module._load (module.js:439:3)
at Module.require (module.js:498:17)
at require (internal/module.js:20:19)
at Object.(/home/mm/MagicMirror/node_modules/electron/cli.js:3:16)
at Module._compile (module.js:571:32)npm ERR! Linux 4.4.48-2-ARCH
npm ERR! argv "/usr/bin/node" "/usr/bin/npm" "start"
npm ERR! node v7.5.0
npm ERR! npm v4.2.0
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! [email protected] start:sh run-start.sh
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the [email protected] start script 'sh run-start.sh'.
npm ERR! Make sure you have the latest version of node.js and npm installed.
npm ERR! If you do, this is most likely a problem with the magicmirror package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR! sh run-start.sh
npm ERR! You can get information on how to open an issue for this project with:
npm ERR! npm bugs magicmirror
npm ERR! Or if that isn't available, you can get their info via:
npm ERR! npm owner ls magicmirror
npm ERR! There is likely additional logging output above.npm ERR! Please include the following file with any support request:
npm ERR! /home/mm/.npm/_logs/2017-02-17T20_32_08_740Z-debug.log
Seems a Electron issue not of the MagicMirror.
I can see the last Electron support is Node 7.4.0

Did you try ask there?
Ohhh, than the Readme.rd is not really correct ("install the latest version of NodeJS") ;-)
I pushed a PL #727 to include Node7 in Travis CI. The tests are passing with Node v7.5.0
https://travis-ci.org/roramirez/MagicMirror/jobs/203279630
What electron version version did install?
./node_modules/electron/dist/electron -v
OMG, all work fine now. I think it was not an Electron issue but much more a config issue. The chromium got a 403 Forbidden when requesting localhost:8080. Here is my config patch:
[mm@mm MagicMirror]$ diff -u config/config.js.back config/config.js
--- config/config.js.back 2017-02-19 10:23:20.742176813 +0000
+++ config/config.js 2017-02-22 20:41:44.906738957 +0000
@@ -7,9 +7,10 @@
height: 1080
},
- address: "10.1.1.192",
+// address: "10.1.1.192",
port: 8080,
ipWhitelist: [
+ "::1",
"10.1.1.25",
"::ffff:10.1.1.25",
],
FYI: Node 7.6.0 works fine ;-)
Thanks for reporting @bh, greatly appreciated!
Most helpful comment
FYI: Node 7.6.0 works fine ;-)