Actions lift property should match the RxJs profile
There is a breaking change in TypeScript version 2.4.1+ and it breaks the hosted VSTS projects if you have not specifically specified typescript version in the package.json file.
Fix the typescript version to 2.4.0 to fix this.
- "typescript": "^2.2.1"
+ "typescript": "2.4.0"
See a related thread here