I updated my angular to v9 and when I try to go back in v8, I receive this error. I have already tried the following:
From my experience a new module that you are using is designed for angular9 and you should upgrade your imports if possible to:
"dependencies": {
"@angular/animations": "^9.1.9",
"@angular/cdk": "^9.2.4",
"@angular/common": "^9.1.9",
"@angular/compiler": "^9.1.9",
"@angular/core": "^9.1.9",
"@angular/forms": "^9.1.9",
"@angular/platform-browser": "^9.1.9",
"@angular/platform-browser-dynamic": "^9.1.9",
"@angular/router": "^9.1.9",
...
}
"devDependencies": {
"@angular-devkit/build-angular": "^0.901.7",
"@angular/cli": "^9.1.7",
"@angular/compiler-cli": "^9.1.9",
"@angular/language-service": "^9.1.9",
...
}