error : The DefaultValue expression for the report parameter ‘AX_CompanyName’ contains an error: Request for the permission of type System.Security.Permissions.EnvironmentPermission

this error occur when I run the SSRS report. Here are to solution :

1. on your windows server that contains SQL Server, go to C:\Program Files\Microsoft SQL Server, then do find the MRS for your environment.

2. find rssrvpolicy.config

3. replace PermissionSetName=”Execution” on class=”UnionCodeGroup” with PermissionSetName=”FullTrust”