I\'ve been running my ASP.NET Core 2.1 Preview-1 app on Azure since this release became available. I had installed the ASP.NET Core runtime extensions through the portal and it\
Try adding a global.json file in your project folder with this content:
global.json
{ "sdk": { "version": "2.1.300-preview2-008530" } }
Restart your app after that to be on the safe side.