<loadFromRemoteSources> Element

Specifies whether assemblies from remote sources should be granted full trust.

Note
If you were directed to this topic because of an error message in the Visual Studio project error list or a build error, see How to: Use an Assembly from the Web in Visual Studio.

<configuration> Element
  <runtime> Element
    <loadFromRemoteSources> Element

<loadFromRemoteSources  
   enabled="true|false"/>

Attributes and Elements

The following sections describe attributes, child elements, and parent elements.

Attributes

enabled Attribute

Child Elements

None.

Parent Elements

Remarks

In the .NET Framework version 3.5 and earlier versions, if you loaded an assembly from a remote location, the assembly would run partially trusted with a grant set that depended on the zone in which it was loaded. For example, if you loaded an assembly from a Web site, it was loaded into the Internet zone and granted the Internet permission set. In other words, it executed in an Internet sandbox. If you try to run that assembly in the .NET Framework version 4, an exception is thrown; you must either explicitly create a sandbox for the assembly, or run it in full trust.

The <loadFromRemoteSources> element lets you specify that the assemblies that run partially trusted in earlier versions of the .NET Framework should be run fully trusted in the .NET Framework 4.

Note
If an application has been copied from the Web, it is flagged by Windows as being a Web application, even if it resides on the local computer. You can change that designation by changing the file properties, or you can use the <loadFromRemoteSources> element to grant the assembly full trust.

The enabled attribute for this element is effective only when code access security (CAS) is disabled. By default, CAS policy is disabled in the .NET Framework 4 and later versions. If you set enabled to true, remote applications are granted full trust.

If <loadFromRemoteSources> enabled is not set to true, an exception is thrown under the following conditions:

• The sandboxing behavior of the current domain is different from its behavior in the .NET Framework 3.5. This requires CAS policy to be disabled, and the current domain not to be sandboxed.

• The assembly being loaded is not from the MyComputer zone.

Note
You may get a FileLoadException in a Windows Virtual PC application when you try to load a file from linked folders on the hosting computer. This error may also occur when you try to load a file from a folder linked over Remote Desktop Services (Terminal Services). To avoid the exception, set enabled to true.

Setting the <loadFromRemoteSources> element to true prevents this exception from being thrown. It enables you to specify that you are not relying on the common language runtime to sandbox the loaded assemblies for security, and that they can be allowed to execute as full trust.

Important
If the assembly should not run in full trust, do not set this configuration element. Instead, create a sandboxed AppDomain in which to load the assembly.

Configuration File

This element can be used only in the application configuration file.

Example

The following example shows how to grant full trust to applications from remote sources.

<configuration>
   <runtime>
      <loadFromRemoteSources enabled="true"/>
   </runtime>
</configuration>

See Also

Reference

Runtime Settings Schema

Other Resources

Configuration File Schema for the .NET Framework