Resolving the "IIS configuration change" issue
If you're running an ASP.NET application in an environment with Windows Server 2012 R2, you may experience an issue which is causing the application to restart frequently after writing to App_Data folder.
An ASP.NET application is restarted every time there are several write operations in the App_Data folder which leads to performance issues. Kentico is using the App_Data folder to store various files (e.g. Smart search indexes) and writes to this folder quite often. When this issue happens, IIS incorrectly detects configuration change and causes the application to restart.
You can identify this issue by searching for an ApplicationEnd event in the Kentico Event log application with the following message:
Message: IIS configuration change
HostingEnvironment initiated shutdown
HostingEnvironment caused shutdown
To fix the issue, please follow KB3052480 Microsoft KB article.