Technical Notes

When attempting to run a .NET web application built with Web Builder, you may see a Server Error "Could not load file or assembly AppConn.Interop." This technical note describes the error and solution.

Problem Symptom

When attempting to run a .NET web application built with Web Builder (in the Verastream Host Integrator [VHI] Development Kit), an error may be displayed in the web browser such as the following.

The Exception Details section indicates System.IO.FileNotFoundException with the above error repeated.

The Source Error section may indicate the exception occurred when executing the following line:

Explanation

The issue cause depends on your product version.

Version 6.5

This problem may occur if you installed a hotfix (version 6.5.707 or higher), uninstalled the product from Add/Remove Programs, and then re-install the shipping release (version 6.5.683).

Version 6.0

This problem occurs if Microsoft .NET Framework version 1.1 was not installed before Verastream Host Integrator 6.0.

This problem occurs even if .NET Framework version 2.0 has been installed. VHI 6.0 Setup expects .NET Framework version 1.1 to be present.

During VHI 6.0 installation, DLL components are normally registered using the Global Assembly Cache Tool provided with Microsoft .NET Framework 1.1 (C:\Windows\Microsoft.NET\Framework\v1.1.4322\gacutil.exe). If the tool is not found in this location, the DLL files are not registered.

Solution

You can manually register the Verastream DLLs, using either the Control Panel Method or Command Prompt Method.

Note: If you uninstalled and re-installed the product after applying a version 6.5 hotfix, refer to the hotfix ReadMe for instructions on using VHI_GAC_Upgrade.zip.

Control Panel Method

Follow the steps below to resolve this issue using the graphical configuration utility:

1. In Control Panel, open Administrative Tools.
2. Open Microsoft .NET Framework (1.1 or 2.0) Configuration.
3. In the left pane, click Assembly Cache (or click "Manage Assembly Cache" in the right pane).
4. Before proceeding, view the list of assemblies in the Assembly Cache and verify that AppConn.Interop is not listed.
5. In the right pane, click "Add an Assembly to the Assembly Cache" (or right-click Assembly Cache and click Add).
6. In the "Add an Assembly" browse dialog, go to C:\Program Files\VHI\lib\dotnet and select all DLL files that are present.

7. View the list of assemblies in the Assembly Cache and verify that the added files are present.

Note: If you have already been running a web application that calls the VHI connector, certain DLL files remain loaded by IIS and locked. For changes to take effect, you may need to restart your system, or terminate the aspnet_wp.exe process in Windows Task Manager.

Command Prompt Method

Instead of using the Control Panel configuration utility above, you can register the VHI DLL files using the command line to run gacutil.exe (installed with .NET Framework SDK 2.0, or .NET Framework 1.1). For example,

Note: You must have administrative privileges to run gacutil.exe.

To verify that the files are successfully added, examine the C:\Windows\Assembly directory, or run gacutil /l.