Random error in RDLC - Access to the path C:\Windows\TEMP - asp.net-mvc

Question

I am trying to generate a rdlc report and save it as pdf. It works perfectly fine on the localhost but after deploying it on the server after successfully generation of some files it stops randomly with below exception
System.UnauthorizedAccessException
Access to the path 'C:\Windows\TEMP\expression_host_791eafe958ba48999639e489485a25c1.dll' is denied.
I have tried giving full access to IUSR, IIS_IUSRS, IIS APPPOOL\MyPOOL, NetworkService and even disposing my localreport and setting permissions, example code below:
using (var lr = new LocalReport())
{
PermissionSet permissions = new PermissionSet(PermissionState.None);
permissions.AddPermission(new FileIOPermission(PermissionState.Unrestricted));
permissions.AddPermission(new SecurityPermission(SecurityPermissionFlag.Execution));
lr.SetBasePermissionsForSandboxAppDomain(permissions);
I even restarted the server, recycled app pool and also tried resetting IIS by aspnet_regiis -i
Nothing worked till now. Any help would be really appreciated.

Answer 1

This mostly an IIS issue.
Change the AppPool's Identity to LocalSystem, you shouldn't get the errors

Answer 2

I had the same scenario you described "It works perfectly fine on the localhost but after deploying it on the server...". What worked for me was:
1- check the new directory where the .rdlc file is located on the server. Get the full path
2- make sure the file and directory are the same in your code (and you're not pointing to the same old location, localhost)