Security Policy Exception on IIS

My site works without any problems, after installing IIS(ASPNet 4.7) as default. But I encounter an error message about Policy Exception after installing Maestro Panel (Full Installation). When I don’t select the option to download Web Server part during installation, my problem goes away. By the way, IIS 8.0 Express is also installed with Maestro Panel. I have already had IIS 10. Is it possible to crash between these two versions? And when I add my web site on IIS Manager, I saw that many extension definitions that should normally be in Handler Mapping were deleted. It is weird.Isn’t it? I am waiting for your suggestions to solve my problem..

My Error Message:

Required permissions cannot be acquired. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Security.Policy.PolicyException: Required permissions cannot be acquired.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[PolicyException: Required permissions cannot be acquired.] System.Security.SecurityManager.ResolvePolicy(Evidence evidence, PermissionSet reqdPset, PermissionSet optPset, PermissionSet denyPset, PermissionSet& denied, Boolean checkExecutionPermission) +7628755 System.Security.SecurityManager.ResolvePolicy(Evidence evidence, PermissionSet reqdPset, PermissionSet optPset, PermissionSet denyPset, PermissionSet& denied, Int32& securitySpecialFlags, Boolean checkExecutionPermission) +57

[FileLoadException: Could not load file or assembly 'Syncfusion.XlsIO.Base, Version=14.3350.0.49, Culture=neutral, PublicKeyToken=3d67ed1f87d44c89' or one of its dependencies. Failed to grant minimum permission requests. (Exception from HRESULT: 0x80131417)] System.Reflection.Assembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, Assembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection) +0 System.Reflection.Assembly.nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, Assembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection) +43 System.Reflection.Assembly.InternalLoad(AssemblyName assemblyRef, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) +127 System.Reflection.Assembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) +142 System.Reflection.Assembly.Load(String assemblyString) +28 System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) +46

[ConfigurationErrorsException: Could not load file or assembly 'Syncfusion.XlsIO.Base, Version=14.3350.0.49, Culture=neutral, PublicKeyToken=3d67ed1f87d44c89' or one of its dependencies. Failed to grant minimum permission requests. (Exception from HRESULT: 0x80131417)] System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) +613 System.Web.Configuration.CompilationSection.LoadAllAssembliesFromAppDomainBinDirectory() +203 System.Web.Configuration.CompilationSection.LoadAssembly(AssemblyInfo ai) +105 System.Web.Compilation.BuildManager.GetReferencedAssemblies(CompilationSection compConfig) +178 System.Web.Compilation.WebDirectoryBatchCompiler..ctor(VirtualDirectory vdir) +163 System.Web.Compilation.BuildManager.BatchCompileWebDirectoryInternal(VirtualDirectory vdir, Boolean ignoreErrors) +53 System.Web.Compilation.BuildManager.BatchCompileWebDirectory(VirtualDirectory vdir, VirtualPath virtualDir, Boolean ignoreErrors) +175 System.Web.Compilation.BuildManager.CompileWebFile(VirtualPath virtualPath) +86 System.Web.Compilation.BuildManager.GetVPathBuildResultInternal(VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile) +261 System.Web.Compilation.BuildManager.GetVPathBuildResultWithNoAssert(HttpContext context, VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile) +101 System.Web.Compilation.BuildManager.GetVirtualPathObjectFactory(VirtualPath virtualPath, HttpContext context, Boolean allowCrossApp, Boolean noAssert) +126 System.Web.Compilation.BuildManager.CreateInstanceFromVirtualPath(VirtualPath virtualPath, Type requiredBaseType, HttpContext context, Boolean allowCrossApp, Boolean noAssert) +62 System.Web.UI.PageHandlerFactory.GetHandlerHelper(HttpContext context, String requestType, VirtualPath virtualPath, String physicalPath) +33 System.Web.UI.PageHandlerFactory.GetHandler(HttpContext context, String requestType, String virtualPath, String path) +37 System.Web.MaterializeHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +307 System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155

That exception indicates a code access security failure to assert in a partial trust environment. Partial trust is obsolete and has been for over 10 years.

You may want to check your .config file(s) to ensure there isn't anything ancient like using CLR 2.0. Or anything related to code access security.

More information:

https://www.syncfusion.com/kb/2407/failed-to-load-the-syncfusion-assembly-due-to-exception-failed-to-grant-minimum-permission