I wrote a custom delivery extension for ssrs 2008. It is working fine in about 12 different servers (dev, test and production) except for one production server where I keep getting the error below: Note: I've compared the rsreportserver.config, and the rssrvpolicy.config files in the ReportServer and ReportManager folders. Like I said, i've deployed this custom delivery extension in other servers but keeps failing in this one. my servers are all runing the same version of SSRS (Microsoft SQL Server Reporting Services Version 10.0.2734.0 ) Does anybody know what I might be missing? I enabled the fusion logging but it is not very helpful. ERROR: Exception caught instantiating MyCustomDelivery report server extension: System.IO.FileLoadException: Could not load file or assembly 'myCustomDelivery' or one of its dependencies. Access is denied. File name: 'myCustomDelivery' at System.Reflection.Assembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, Assembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection) at System.Reflection.Assembly.InternalLoad(AssemblyName assemblyRef, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) at System.Reflection.Assembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) at System.Reflection.Assembly.Load(String assemblyString) at Microsoft.ReportingServices.Diagnostics.ExtensionClassFactory.LoadAssembly(String name) at Microsoft.ReportingServices.Diagnostics.ExtensionClassFactory.<>c__DisplayClass2.<CreateExtensionObject>b__0() at Microsoft.ReportingServices.Diagnostics.RevertImpersonationContext.<>c__DisplayClass1.<Run>b__0(Object state) at System.Security.SecurityContext.runTryCode(Object userData) at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData) at System.Security.SecurityContext.Run(SecurityContext securityContext, ContextCallback callback, Object state) at Microsoft.ReportingServices.Diagnostics.RevertImpersonationContext.Run(ContextBody callback) at Microsoft.ReportingServices.Diagnostics.ExtensionClassFactory.CreateExtensionObject(Extension extConfig, Boolean typeOnly) === Pre-bind state information === LOG: User = domain\edarsanchez40 LOG: DisplayName = myCustomDelivery (Partial) LOG: Appbase = file:///C:/Program Files/Microsoft SQL Server/MSRS10.SSRS/Reporting Services/ReportServer/ LOG: Initial PrivatePath = C:\Program Files\Microsoft SQL Server\MSRS10.SSRS\Reporting Services\ReportServer\bin;C:\Program Files\Microsoft SQL Server\MSRS10.SSRS\Reporting Services\ReportServer\bin Calling assembly : (Unknown). === LOG: This bind starts in default load context. LOG: Using application configuration file: C:\Program Files\Microsoft SQL Server\MSRS10.SSRS\Reporting Services\ReportServer\web.config LOG: Using machine configuration file from C:\WINDOWS\Microsoft.NET\Framework64\v2.0.50727\config\machine.config. LOG: Policy not being applied to reference at this time (private, custom, partial, or location-based assembly bind). LOG: Attempting download of new URL file:///C:/Program Files/Microsoft SQL Server/MSRS10.SSRS/Reporting Services/RSTempFiles/reportingserver/1545f1e7/41587d91/myCustomDelivery.DLL. LOG: Attempting download of new URL file:///C:/Program Files/Microsoft SQL Server/MSRS10.SSRS/Reporting Services/RSTempFiles/reportingserver/1545f1e7/41587d91/myCustomDelivery/myCustomDelivery.DLL. LOG: Attempting download of new URL file:///C:/Program Files/Microsoft SQL Server/MSRS10.SSRS/Reporting Services/ReportServer/bin/myCustomDelivery.DLL. ERR: Failed to complete setup of assembly (hr = 0x80070005). Probing terminated.