Error messages when executing yarn electron:serve

I’m a newbie of electron.

When launchin electron with yarn electron: serve, I get these error messages:
yarn electron:serve
yarn run v1.22.4
$ vue-cli-service electron:serve
INFO Starting development server…
98% after emitting CopyPlugin

 WARNING  Compiled with 2 warnings                                                                                               
9:39:53 AM

 warning  in ./node_modules/gun/sea.js

Critical dependency: the request of a dependency is an expression

 warning  in ./node_modules/gun/gun.js

Critical dependency: the request of a dependency is an expression


  App running at:
  - Local:   http://localhost:8080 
  - Network: http://ggc.world/

  Note that the development build is not optimized.
  To create a production build, run yarn build.

⠦  Bundling main process...

 DONE  Compiled successfully in 573ms                                                                                         
9:39:53 AM

  File                      Size                     Gzipped

  dist_electron/index.js    683.11 KiB               154.67 KiB

  Images and other types of assets omitted.

 INFO  Launching Electron...
Vue Devtools failed to install: ReferenceError: installVueDevtools is not defined
(node:6797) UnhandledPromiseRejectionWarning: TypeError:  
electron__WEBPACK_IMPORTED_MODULE_0__.session.setPermissionRequestHandler is not a 
function
    at App.eval (webpack:///./src/background.js?:95:6)
    at App.emit (events.js:228:7)
(node:6797) UnhandledPromiseRejectionWarning: Unhandled promise rejection. 
This error originated either by throwing inside of an async function without a catch block, or by 
rejecting a promise which was not handled with .catch(). (rejection id: 2)
(node:6797) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. 
In the future, promise rejections that are not handled will terminate the Node.js process with a non-
zero exit code.
menubar:  Error: Image could not be created from /home/marco/webMatters/vueMatters/GGC/assets
/IconTemplate.png
    at Menubar.eval (webpack:///./node_modules/menubar/lib/Menubar.js?:279:60)
    at step (webpack:///./node_modules/menubar/lib/Menubar.js?:57:23)
    at Object.eval [as next] (webpack:///./node_modules/menubar/lib/Menubar.js?:38:53)
    at eval (webpack:///./node_modules/menubar/lib/Menubar.js?:32:71)
    at new Promise (<anonymous>)
    at __awaiter (webpack:///./node_modules/menubar/lib/Menubar.js?:28:12)
    at Menubar.appReady (webpack:///./node_modules/menubar/lib/Menubar.js?:258:16)
    at App.eval (webpack:///./node_modules/menubar/lib/Menubar.js?:95:23)
    at App.emit (events.js:228:7)
MESA-LOADER: failed to retrieve device information
MESA-LOADER: failed to open nouveau (search paths /usr/lib/x86_64-linux-gnu/dri:\$${ORIGIN}
/dri:/usr/lib/dri)
failed to load driver: nouveau
MESA-LOADER: failed to open kms_swrast (search paths /usr/lib/x86_64-linux-gnu/dri:\$${ORIGIN}
/dri:/usr/lib/dri)
failed to load driver: kms_swrast
MESA-LOADER: failed to open swrast (search paths /usr/lib/x86_64-linux-gnu/dri:\$${ORIGIN}
/dri:/usr/lib/dri)
failed to load swrast driver

How to solve the errors?
Looking forward to your kind help.
Marco