当我启动应用程序（离子服务）时，在控制台中出现错误：
[ng] ERROR in ../mts-crosslife/node_modules/@angular/core/esm2015/core.js
[ng] Module not found: Error: Can't resolve 'rxjs/Observable' in '/var/www/mts-crosslife/node_modules/@angular/core/esm2015'
[ng] ERROR in ../mts-crosslife/node_modules/@angular/core/esm2015/core.js
[ng] Module not found: Error: Can't resolve 'rxjs/Subject' in '/var/www/mts-crosslife/node_modules/@angular/core/esm2015'
[ng] ERROR in ../mts-crosslife/node_modules/ionic-angular/es2015/components/input/input.js
[ng] Module not found: Error: Can't resolve 'rxjs/Subject' in '/var/www/mts-crosslife/node_modules/ionic-angular/es2015/components/input'
[ng] ERROR in ../mts-crosslife/node_modules/ionic-angular/es2015/components/tabs/tabs.js
[ng] Module not found: Error: Can't resolve 'rxjs/Subject' in '/var/www/mts-crosslife/node_modules/ionic-angular/es2015/components/tabs'
[ng] ERROR in ../mts-crosslife/node_modules/@angular/core/esm2015/core.js
[ng] Module not found: Error: Can't resolve 'rxjs/Subscription' in '/var/www/mts-crosslife/node_modules/@angular/core/esm2015'
[ng] ERROR in ../mts-crosslife/node_modules/ionic-angular/es2015/components/input/input.js
[ng] Module not found: Error: Can't resolve 'rxjs/add/operator/takeUntil' in '/var/www/mts-crosslife/node_modules/ionic-angular/es2015/components/input'
[ng] ERROR in ../mts-crosslife/node_modules/ionic-angular/es2015/components/tabs/tabs.js
[ng] Module not found: Error: Can't resolve 'rxjs/add/operator/takeUntil' in '/var/www/mts-crosslife/node_modules/ionic-angular/es2015/components/tabs'
[ng] ERROR in ../mts-crosslife/node_modules/@angular/forms/esm2015/forms.js
[ng] Module not found: Error: Can't resolve 'rxjs/observable/forkJoin' in '/var/www/mts-crosslife/node_modules/@angular/forms/esm2015'
[ng] ERROR in ../mts-crosslife/node_modules/@angular/forms/esm2015/forms.js
[ng] Module not found: Error: Can't resolve 'rxjs/observable/fromPromise' in '/var/www/mts-crosslife/node_modules/@angular/forms/esm2015'
[ng] ERROR in ../mts-crosslife/node_modules/@angular/core/esm2015/core.js
[ng] Module not found: Error: Can't resolve 'rxjs/observable/merge' in '/var/www/mts-crosslife/node_modules/@angular/core/esm2015'
[ng] ERROR in ../mts-crosslife/node_modules/@angular/forms/esm2015/forms.js
[ng] Module not found: Error: Can't resolve 'rxjs/operator/map' in '/var/www/mts-crosslife/node_modules/@angular/forms/esm2015'
[ng] ERROR in ../mts-crosslife/node_modules/@angular/core/esm2015/core.js
[ng] Module not found: Error: Can't resolve 'rxjs/operator/share' in '/var/www/mts-crosslife/node_modules/@angular/core/esm2015'
已安装RXJS：
"rxjs": "~6.5.1",
"rxjs-compat": "^6.5.5"
如何解决这些错误？