CCL1043: Error when launching development server 'Callback was already called.'

[Ryan Magsam1]

I get this error when launching the dev server. Any ideas how to resolve this one?

ryan@m-c02cm0symd6r ccl1043 % snc ui-component develop --open
Running component locally...
Proxy server connecting to https://nowlearning-lpt0397125-001.lab.service-now.com
clean-webpack-plugin: /Users/ryan/ccl1043/dist is outside of the project root. Skipping...
 10% building modules 1/1 modules 0 active(node:86120) [DEP0131] DeprecationWarning: The legacy HTTP parser is deprecated.
(node:86120) DeprecationWarning: Tapable.plugin is deprecated. Use new API on `.hooks` instead
(node:86120) DeprecationWarning: Tapable.apply is deprecated. Call apply on the plugin directly instead
ℹ ｢wds｣: Project is running at http://localhost:8081/
ℹ ｢wds｣: webpack output is served from /
ℹ ｢wds｣: Content not from webpack is served from /Users/ryan/ccl1043/dist, /Users/ryan/ccl1043/node_modules/sn-polyfills/dist
ℹ ｢wds｣: 404s will fallback to /index.html
 10% building modules 1/6 modules 5 active …sers/ryan/ccl1043/example/element.jsℹ ｢wdm｣: wait until bundle finished: /
 10% building modules 5/6 modules 1 active …sers/ryan/ccl1043/example/element.js✖ ｢wdm｣: TypeError: dep.getResourceIdentifier is not a function
    at addDependency (/Users/ryan/ccl1043/node_modules/@servicenow/cli-component-archetype-dev/node_modules/webpack/lib/Compilation.js:413:30)
    at iterationOfArrayCallback (/Users/ryan/ccl1043/node_modules/@servicenow/cli-component-archetype-dev/node_modules/webpack/lib/Compilation.js:88:3)
    at addDependenciesBlock (/Users/ryan/ccl1043/node_modules/@servicenow/cli-component-archetype-dev/node_modules/webpack/lib/Compilation.js:435:5)
    at Compilation.processModuleDependencies (/Users/ryan/ccl1043/node_modules/@servicenow/cli-component-archetype-dev/node_modules/webpack/lib/Compilation.js:446:4)
    at afterBuild (/Users/ryan/ccl1043/node_modules/@servicenow/cli-component-archetype-dev/node_modules/webpack/lib/Compilation.js:569:15)
    at /Users/ryan/ccl1043/node_modules/@servicenow/cli-component-archetype-dev/node_modules/webpack/lib/Compilation.js:613:11
    at callback (/Users/ryan/ccl1043/node_modules/@servicenow/cli-component-archetype-dev/node_modules/webpack/lib/Compilation.js:364:5)
    at /Users/ryan/ccl1043/node_modules/@servicenow/cli-component-archetype-dev/node_modules/webpack/lib/Compilation.js:404:12
    at handleParseResult (/Users/ryan/ccl1043/node_modules/@servicenow/cli-component-archetype-dev/node_modules/webpack/lib/NormalModule.js:458:12)
    at /Users/ryan/ccl1043/node_modules/@servicenow/cli-component-archetype-dev/node_modules/webpack/lib/NormalModule.js:480:6
    at /Users/ryan/ccl1043/node_modules/@servicenow/cli-component-archetype-dev/node_modules/webpack/lib/NormalModule.js:344:12
    at /Users/ryan/ccl1043/node_modules/loader-runner/lib/LoaderRunner.js:373:3
    at iterateNormalLoaders (/Users/ryan/ccl1043/node_modules/loader-runner/lib/LoaderRunner.js:214:10)
    at iterateNormalLoaders (/Users/ryan/ccl1043/node_modules/loader-runner/lib/LoaderRunner.js:221:10)
    at /Users/ryan/ccl1043/node_modules/loader-runner/lib/LoaderRunner.js:236:3
    at context.callback (/Users/ryan/ccl1043/node_modules/loader-runner/lib/LoaderRunner.js:111:13)

/Users/ryan/ccl1043/node_modules/neo-async/async.js:16
    throw new Error('Callback was already called.');
          ^
Error: Callback was already called.
    at throwError (/Users/ryan/ccl1043/node_modules/neo-async/async.js:16:11)
    at /Users/ryan/ccl1043/node_modules/neo-async/async.js:2818:7
    at processTicksAndRejections (internal/process/task_queues.js:79:11)
ryan@m-c02cm0symd6r ccl1043 % 

[Robert Ninness · Accepted solution]

Hi Ryan,

I'm not sure about this error. If you are getting odd errors which you can't trace back to changes you have made to the code, then sometimes it helps to re-import all of the dependencies.

To do this run npm install

If that doesn't work, try deleting the node_modules folder and running the npm install command again.

Let me know if you are still having issues.

[Ryan Magsam1]

That helped.  Thanks for pushing us kicking and screaming into a NodeJS and ES6 world!

[Arnoud Kooi]

If other people run into this issue, for me I had to reinstall my node version as well.
It seems that it had some conflicting packages. I'm using nvm to switch node modules.
Steps that worked for me are: 

nvm use node #switch so your not using version to uninstall
nvm uninstall v12.22.9 #uninstall
nvm install v12.22.9 #reinstall
nvm use v12.22.9 #use correct version
rm -rf node_modules && rm package-lock.json #cleanup all old node stuff
node install #reinstalll
snc ui-component develop #hope it works now!!

In this article I'm publishing some common issues you may encounter with the CLI / Custom Components