ASP.NET app unable to write to file in IIS8 WS2012

Question

In the middle of migrating sites and scripts from WS2008/IIS7.5 to WS2012/IIS8. These sites and scripts write logs to text files with no issues in our old env. On our new server, the sites are not able to write logs but our scripts have no issues. This doesn't look to be a permission issue as we have granted permissions to folders using IIS APPPOOL\WEBAPPNAME. Is there a new setting in IIS8 that is preventing these apps from writing these logs?

-Authentication > Anonymous Authentication > Application Pool Identity > IIS APPPOOL\WEBAPPNAME

-Permission to log folder > IIS APPPOOL\WEBAPPNAME > FULL CONTROL

Answer 1

Rather than tricking with permissions, I suggest you to check with following options:

Option 1: Change your website application pool identity from default to super user of your account. Make sure that, your file must have FULL CONTROL for file creator/owner.

If above option does not work then you can go to trick with permissions. Please add IUSER to your file and give write permissions to it.

That's it!