ASP.NET Core hosting - 500 internal server error

I have also enabled stdoutLog in web.config as but I don't see that folder either:

stdoutLogEnabled="true" stdoutLogFile=".\logs\stdout"

There is one trick here - you must create both folders logs and stdout manually - then and only then IIS will create log file inside logs folder (not stdout as you could expect) - don't ask me why, because I don't know why ;)

Oops. 500 Internal Server Error An error occurred while starting the application.

Usually, means problems with a configuration in Startup.cs - the most common problems include an issue with DB itself, an issue with migrations (if you are using Code First approach), problems with appsettings.js, problems with Social Logins credentials (like missing SecretKey)...

Please refer to log file in .\logs\stdout - this is the quickest way to find details about the problem :)

app.UseDeveloperExceptionPage();

app.UseDatabaseErrorPage();

Those will work after your WebApp fully started, but not while starting the application.

in web.config file change modules="AspNetCoreModuleV2" to modules="AspNetCoreModule"

and watch this video https://www.youtube.com/watch?v=clCR3k6kkD8

Thanks to Lukasz for his comments. I was able to see the log and it stated that "ClientId option must be provided". The problem was with the UserSecrets. Since secrets.json is only available in Development, there were no secrets found in Production. Once I had the secrets in my appSettings.json, it worked fine.

Moreover, To replicate this in Local environment, just go to Project properties and change the environment variable ASPNETCORE_ENVIRONMENT to 'Production' and run in local. This will replicate the 500 Internal Server Error in local and you'll get the error message.