I have executed one scenario which has one script with 50 vuser. 25 vuser has failed and 25 vuser has passed.
Now I need to know :
1. which user ID's are failed.
2. In which transaction it has failed.
How to check this out? In which log file I need to check?
If your vusers failed, you should get error on some requests/pages for them displayed in the Errors tab of your test results. Then you should see the user instance of the vuser and on which transaction it happened.
If your application did not return any errors then i would suggest you to add validations at some critical transactions so if they fail you will get an assertion error raised by NeoLoad.