HOW TO: Troubleshoot Problems That Are Related to Trust Levels

This step-by-step article discusses how to troubleshoot problems that are related to trust levels.

Managed assemblies are assigned trust levels that define what resources the assembly, and applications that use the assembly, will have access to. When an assembly is assigned permissions that are too restrictive, it does not function correctly. In highly restrictive environments, this is a common source of problems. This article describes how to isolate and resolve problems that are related to trust levels.

Note These steps require you to grant additional privileges to the assembly. Microsoft recommends that you follow these steps only when you are confident that the assembly does not pose a security risk.

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Identify the Current Trust Level Assigned to an Assembly

When an assembly is assigned full trust, security policy restrictions are not applied to an assembly and you can be confident trust level is not the source of a problem.

For additional information and to evaluate the trust level that is assigned to an assembly, click the following article number to view the article in the Microsoft Knowledge Base: When the permissions that are assigned to the assembly are unrestricted, the trust level that is to assigned the assembly is not causing the problem.

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Determine Whether the Trust Level is the Source of the Problem

Trust levels are assigned by using the .NET Framework Configuration snap-in. A quick way to determine whether restrictive trust levels are the source of a problem is to temporarily grant full access to the assembly and determine whether the problem still occurs. To grant full access to the assembly, follow these steps:

1. Click Start, point to Settings, and then click Control Panel.
2. Double-click to open Administrative Tools, and then double-click to start the Microsoft .NET Framework Configuration tool.
3. Right-click Runtime Security Policy, and then select Trust Assembly. The Trust An Assembly wizard appears.
4. On the What Would You Like to Modify page, leave Make changes to this computer selected, and then click Next.
5. On the Which Assembly Do You Want to Trust page, click Browse and select the assembly that is the source of the problem. Click Open, and then click Next.
6. On the Choose the Minimum Level of Trust for the Assembly page, move the slider to Full Trust, and then click Next.
7. On the Completing the Wizard page, click Finish.

Test the assembly to determine whether the problem still occurs. The assembly is now free from security policy restrictions, and if the problem remains, you can be confident that it is not caused by the trust level. When this is the case, restore the default trust level assigned to the assembly by repeating the previous steps and clicking (in step 6) None on the Choose The Minimum Level of Trust For the Assembly page.

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Adjust the Trust Level

If temporarily assigning full trust to an assembly resolves the problem, you know that the assembly requires greater trust than is typically assigned to it. To identify the lowest level of trust that an assembly requires to execute, assign the lowest trust possible and gradually increase that level of trust until the assembly executes correctly. To set the appropriate trust level to the assembly, follow these steps:

1. Click Start, point to Settings, and then click Control Panel.
2. Double-click to open Administrative Tools, and then double-click to start the Microsoft .NET Framework Configuration tool.
3. Right-click Runtime Security Policy, and then click Trust Assembly. The Trust an Assembly wizard appears.
4. On the What Would You Like to Modify page, leave Make changes to this computer selected, and then click Next.
5. On the Which Assembly Do You Want to Trust page, click Browse and select the assembly that is the source of the problem. Click Open, and then click Next.
6. On the Choose the Minimum Level of Trust for the Assembly page, move the slider to second position from the bottom, and then click Next.
7. On the Completing the Wizard page, click Finish.
8. Test the assembly.
   • If the assembly functions correctly, the assembly requires the Low trust level to execute.
   • If the assembly does not function, repeat steps 2 through 6, and on the Choose the Minimum Level of Trust for the Assemblypage (step 6), move the slider to third position from the bottom. If the assembly functions, it requires the High trust level to execute.
   • If the assembly does not function when granted Low or High trust levels, it requires Full trust to execute. Repeat steps 2 through 6 and assign Full trust to the assembly.

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For additional information, click the following article numbers to view the articles in the Microsoft Knowledge Base: back to the top