Unable to load CLR Instance (wwDotnetBridge)

If you get the error:

Cannot load CLR Instance

it means the wwDotnetBridge wasn't able to load an instance of the self-hosted .NET runtime.

Installation from a Network or Downloaded Zip File

The most common problem is that that the wwDotnetBridge.dll, which is used as the initial DLL for the .NET loader in wwDotnetBridge, is locked by Windows as an insecure Dll. .NET won't load an insecure DLL initially.

If you installed the wwDotnetBridge.dll from a zip file directly from an Internet download, wwDotnetBridge.dll file might be blocked by Windows. If you are running with User Account Control on, the .NET Runtime will not be allowed to load from loading this file.

To fix this, find wwdotnetbridge.dll in Explorer and then right click, select Properties and then Unblock. This will remove the download flag and allow the DLL to be treated as a local file.

Note that this applies only to downloaded instances of the DLL or a ZIP file that the DLL ships in (such as wwClient.zip).

For your own applications, if you install wwDotnetBridge.dll as part as a full installation program the file will be properly installed and no unblocking is required.

.NET Runtime or requested .NET Runtime Version not installed

Another issue that might cause the runtime to fail to load is, if the .NET runtime is not present. If no version of .NET is installed or you are explicitly trying to load a version that is not installed (ie. use V4 when only V2 is installed) you will also get this error.

To verify this issue check the \Windows\Microsoft .NET\Framework folder and check what versions are actually installed on the target system.


© West Wind Technologies, 2004-2020 • Updated: 09/29/15
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