Sorry for my english…
But my MM reboot again and again.

~/MagicMirror/installers $ sh mm.sh 

> magicmirror@2.12.0 start /home/pi/MagicMirror
> DISPLAY="${DISPLAY:=:0}" ./node_modules/.bin/electron js/electron.js

/home/pi/MagicMirror/node_modules/electron/dist/electron: error while loading shared libraries: |ibffi.so.6: cannot open shared object file: No such file or directory
npm ERR! code ELIFECYCLE
npm ERR! syscall spawn
npm ERR! file sh
npm ERR! errno ENOENT
npm ERR! magicmirror@2.12.0 start: `DISPLAY="${DISPLAY:=:0}" ./node_modules/.bin/electron js/electron.js`
npm ERR! spawn ENOENT
npm ERR! 
npm ERR! Failed at the magicmirror@2.12.0 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /home/pi/.npm/_logs/2020-07-15T20_28_46_768Z-debug.log

/home/pi/.npm/_logs/2020-07-15T20_28_46_768Z-debug.log

0 info it worked if it ends with ok
1 verbose cli [ '/usr/bin/node', '/usr/bin/npm', 'start' ]
2 info using npm@6.14.5
3 info using node@v10.20.1
4 verbose run-script [ 'prestart', 'start', 'poststart' ]
5 info lifecycle magicmirror@2.12.0~prestart: magicmirror@2.12.0
6 info lifecycle magicmirror@2.12.0~start: magicmirror@2.12.0
7 verbose lifecycle magicmirror@2.12.0~start: unsafe-perm in lifecycle true
8 verbose lifecycle magicmirror@2.12.0~start: PATH: /usr/lib/node_modules/npm/node_modules/npm-lifecycle/node-gyp-bin:/home/pi/MagicMirror/node_module$
9 verbose lifecycle magicmirror@2.12.0~start: CWD: /home/pi/MagicMirror
10 silly lifecycle magicmirror@2.12.0~start: Args: [ '-c',
10 silly lifecycle   'DISPLAY="${DISPLAY:=:0}" ./node_modules/.bin/electron js/electron.js' ]
11 info lifecycle magicmirror@2.12.0~start: Failed to exec start script
12 verbose stack Error: magicmirror@2.12.0 start: `DISPLAY="${DISPLAY:=:0}" ./node_modules/.bin/electron js/electron.js`
12 verbose stack spawn ENOENT
12 verbose stack     at ChildProcess.<anonymous> (/usr/lib/node_modules/npm/node_modules/npm-lifecycle/lib/spawn.js:48:18)
12 verbose stack     at ChildProcess.emit (events.js:198:13)
12 verbose stack     at maybeClose (internal/child_process.js:982:16)
12 verbose stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:259:5)
13 verbose pkgid magicmirror@2.12.0
14 verbose cwd /home/pi/MagicMirror
15 verbose Linux 4.19.97-v7+
16 verbose argv "/usr/bin/node" "/usr/bin/npm" "start"
17 verbose node v10.20.1
18 verbose npm  v6.14.5
19 error code ELIFECYCLE
20 error syscall spawn
21 error file sh
22 error errno ENOENT
23 error magicmirror@2.12.0 start: `DISPLAY="${DISPLAY:=:0}" ./node_modules/.bin/electron js/electron.js`
23 error spawn ENOENT
24 error Failed at the magicmirror@2.12.0 start script.
24 error This is probably not a problem with npm. There is likely additional logging output above.
25 verbose exit [ 1, true ]

Thanks a lot in advance

I have try : npm rebuild / npm install