Attempt to invoke virtual method 'java.lang.String org.webrtc.MediaStream.getId()' on a null object reference

[hrueger]

Make sure to check the demo app(s) for sample usage

I did.

Make sure to check the existing issues in this repository

I did.

If the demo apps cannot help and there is no issue for your problem, tell us about it

I ran into the same issue as #31 . So I searched on the internet and found out that it could be a problem with the multi dex config. My app.gradle looks like this:

dependencies {
  compile 'com.android.support:multidex:1.0.0'
}

android {  
  defaultConfig {  
    generatedDensities = []
    applicationId = "tld.domain.subdomain" 
    multiDexEnabled true  
  }  
  aaptOptions {  
    additionalParameters "--no-version-vectors"  
  }
  compileOptions {
        sourceCompatibility 1.8
        targetCompatibility 1.8
  }
} 
def settingsGradlePath
if(project.hasProperty("appResourcesPath")){
    settingsGradlePath = "$project.appResourcesPath/Android/settings.gradle";
} else {
    settingsGradlePath = "$rootDir/../../app/App_Resources/Android/settings.gradle";
}
def settingsGradleFile = new File(settingsGradlePath);
if(settingsGradleFile.exists())
{
    apply from: settingsGradleFile;
}

I added android.enableDexingArtifactTransform.desugaring=false to the App_Ressources/Android/gradle.properties which solved #31 . But now, once I open the call component which includes the readme's sample code, I get this error message after I got asked for the camera and microphone permissions:

Which platform(s) does your issue occur on?

• iOS/Android/Both: only Android
• iOS/Android versions: I've tested with android 9, I don't know about the other versions.
• emulator or device. What type of device: Real device

Please, provide the following version numbers that your issue occurs with:

• CLI: 6.3.0
• Cross-platform modules: 6.3.2
• Runtime(s): 6.3.0
• Plugin(s):

  "dependencies": {
      "@angular/animations": "^8.2.14",
      "@angular/cdk": "^8.2.3",
      "@angular/common": "8.2.14",
      "@angular/compiler": "8.2.14",
      "@angular/core": "8.2.14",
      "@angular/fire": "5.2.3",
      "@angular/forms": "8.2.14",
      "@angular/http": "7.2.15",
      "@angular/platform-browser": "8.2.14",
      "@angular/platform-browser-dynamic": "8.2.14",
      "@angular/router": "8.2.14",
      "@ctrl/ngx-emoji-mart": "1.0.5",
      "@fortawesome/fontawesome-free": "5.12.0",
      "@nativescript/theme": "2.2.1",
      "@ng-bootstrap/ng-bootstrap": "5.1.4",
      "@ngx-translate/core": "^11.0.1",
      "@ngx-translate/http-loader": "^4.0.0",
      "@nstudio/nativescript-pulltorefresh": "1.1.1",
      "@nstudio/nativescript-snackbar": "^1.1.1",
      "@syncfusion/ej2-angular-inputs": "^17.4.39",
      "@syncfusion/ej2-angular-layouts": "^17.4.40",
      "@syncfusion/ej2-angular-navigations": "^17.4.39",
      "@syncfusion/ej2-angular-popups": "^17.4.39",
      "@syncfusion/ej2-angular-schedule": "^17.4.39",
      "@syncfusion/ej2-layouts": "^17.4.40",
      "ajv": "^6.10.2",
      "angularx-flatpickr": "^6.2.0",
      "bootstrap": "^4.4.1",
      "chart.js": "^2.9.3",
      "chartjs-plugin-datalabels": "^0.7.0",
      "cldr-data": "^36.0.0",
      "core-js": "^3.6.1",
      "date-fns": "^2.8.1",
      "firebase": "^7.6.1",
      "fontawesome": "^5.6.3",
      "nativescript-accordion": "^6.0.0-beta.2",
      "nativescript-angular": "8.20.3",
      "nativescript-animated-circle": "^1.2.0",
      "nativescript-appversion": "^1.4.4",
      "nativescript-background-http": "^4.2.1",
      "nativescript-cache": "^1.0.0",
      "nativescript-camera": "^4.5.0",
      "nativescript-carousel": "^6.1.1",
      "nativescript-cfalert-dialog": "^1.0.15",
      "nativescript-clipboard": "^1.2.0",
      "nativescript-contacts-lite": "^0.2.6",
      "nativescript-downloader": "2.1.5",
      "nativescript-emoji-picker": "0.2.4",
      "nativescript-exit": "^1.0.1",
      "nativescript-feedback": "^1.3.12",
      "nativescript-geolocation": "^5.1.0",
      "nativescript-image-swipe": "^5.0.1",
      "nativescript-letter-avatar": "^0.2.0",
      "nativescript-local-notifications": "^4.1.4",
      "nativescript-localstorage": "^2.0.1",
      "nativescript-mediafilepicker": "^2.0.18",
      "nativescript-modal-datetimepicker": "^1.2.1",
      "nativescript-multi-select": "^1.0.6",
      "nativescript-ngx-fonticon": "^5.0.2",
      "nativescript-pdf-view": "^2.1.0",
      "nativescript-photo-editor": "^1.1.0",
      "nativescript-plugin-firebase": "^10.3.3",
      "nativescript-progress-notifications": "^1.0.1",
      "nativescript-ui-autocomplete": "6.0.0",
      "nativescript-ui-calendar": "6.0.0",
      "nativescript-ui-chart": "7.1.1",
      "nativescript-ui-dataform": "6.0.0",
      "nativescript-ui-gauge": "6.0.0",
      "nativescript-ui-listview": "8.0.1",
      "nativescript-ui-sidedrawer": "8.0.0",
      "nativescript-videoplayer": "^4.2.1",
      "nativescript-webrtc-plugin": "^2.0.0-alpha.19",
      "ng2-charts": "^2.3.0",
      "ngx-avatar": "^3.7.0",
      "ngx-contextmenu": "^5.3.0",
      "ngx-extended-pdf-viewer": "^1.8.4",
      "ngx-lightbox": "^2.1.1",
      "ngx-onlyoffice": "^0.0.4",
      "ngx-toastr": "^11.2.1",
      "reflect-metadata": "~0.1.13",
      "rxjs": "^6.5.4",
      "rxjs-compat": "^6.5.4",
      "tns-core-modules": "6.3.2",
      "zone.js": "0.10.2"
  },
  "devDependencies": {
      "@angular-devkit/build-angular": "0.803.21",
      "@angular/cli": "^8.3.21",
      "@angular/compiler-cli": "8.2.14",
      "@nativescript/schematics": "^1.0.0",
      "@types/jasmine": "~3.5.0",
      "@types/jasminewd2": "^2.0.8",
      "@types/node": "^12.12.21",
      "codelyzer": "~5.2.1",
      "jasmine-core": "~3.5.0",
      "jasmine-spec-reporter": "~4.2.1",
      "karma": "~4.4.1",
      "karma-chrome-launcher": "~3.1.0",
      "karma-coverage-istanbul-reporter": "^2.1.1",
      "karma-jasmine": "~2.0.1",
      "karma-jasmine-html-reporter": "^1.5.1",
      "nativescript-dev-webpack": "1.4.0",
      "node-sass": "4.13.0",
      "protractor": "~5.4.2",
      "systemjs-plugin-json": "^0.3.0",
      "tns-platform-declarations": "6.3.2",
      "ts-node": "^8.5.4",
      "tslint": "~5.20.1",
      "typescript": "3.5.3"
  },

Please, tell us how to recreate the issue in as much detail as possible.

Create a nativescript (angular) project, change app.gradle to the provided one and add android.enableDexingArtifactTransform.desugaring=false to the App_Ressources/Android/gradle.properties.

Is there any code involved?

See above