TypeScript: Cannot read property 'flags' of undefined

Been dealing with this for months, please fix.

./src/app/auth/auth.manager.ts
Module build failed: TypeError: Cannot read property 'flags' of undefined
    at resolveAlias (C:\Users\brian.cullinan\Documents\portal\node_modules\typescript\lib\typescript.js:28064:36)
    at checkAliasSymbol (C:\Users\brian.cullinan\Documents\portal\node_modules\typescript\lib\typescript.js:46447:26)
    at checkImportBinding (C:\Users\brian.cullinan\Documents\portal\node_modules\typescript\lib\typescript.js:46477:13)
    at Object.forEach (C:\Users\brian.cullinan\Documents\portal\node_modules\typescript\lib\typescript.js:1506:30)
    at checkImportDeclaration (C:\Users\brian.cullinan\Documents\portal\node_modules\typescript\lib\typescript.js:46498:32)
    at checkSourceElement (C:\Users\brian.cullinan\Documents\portal\node_modules\typescript\lib\typescript.js:46789:28)
    at Object.forEach (C:\Users\brian.cullinan\Documents\portal\node_modules\typescript\lib\typescript.js:1506:30)
    at checkSourceFileWorker (C:\Users\brian.cullinan\Documents\portal\node_modules\typescript\lib\typescript.js:46862:20)
    at checkSourceFile (C:\Users\brian.cullinan\Documents\portal\node_modules\typescript\lib\typescript.js:46842:13)
    at getDiagnosticsWorker (C:\Users\brian.cullinan\Documents\portal\node_modules\typescript\lib\typescript.js:46906:17)
    at getDiagnostics (C:\Users\brian.cullinan\Documents\portal\node_modules\typescript\lib\typescript.js:46892:24)
    at Object.getEmitResolver (C:\Users\brian.cullinan\Documents\portal\node_modules\typescript\lib\typescript.js:27162:13)
    at C:\Users\brian.cullinan\Documents\portal\node_modules\typescript\lib\typescript.js:70021:69
    at runWithCancellationToken (C:\Users\brian.cullinan\Documents\portal\node_modules\typescript\lib\typescript.js:69779:24)
    at getDeclarationDiagnosticsForFileNoCache (C:\Users\brian.cullinan\Documents\portal\node_modules\typescript\lib\typescript.js:70020:20)
    at getAndCacheDiagnostics (C:\Users\brian.cullinan\Documents\portal\node_modules\typescript\lib\typescript.js:70033:26)
 @ ./src/app/core/core.module.ts 19:0-51
 @ ./src/app/app.module.ts
 @ ./src/main.ts
 @ multi webpack-dev-server/client?http://localhost:9090 ./src/main.ts

About this issue

Original URL
State: closed
Created 7 years ago
Comments: 21 (10 by maintainers)

Most upvoted comments

I got it to break in the typescript compiler on an Injectable token, but I am not sure what file or anything unusual that is causing it:

I’ll probably hunt around a bit and then try some different versions. Thank you for the good starting point!

ghost on Oct 16, 2017

Cool, just got it to fail in the debugger. Looks like if you are editing a file in watch mode, and you create something invalid like <new line> alert with no semi-colon. Save. Edit, and remove the line alert.
Watch never recovers from errors and just displays this flags error.

ghost on Oct 16, 2017