Licensing ImageMan.Net Twain on a web server requires a few steps that are easily overlooked. Please follow these guidelines when attempting to resolve licensing issues for client side or web applications:
1. Make sure you can navigate to the DTI.ImageMan.Twain.dll file in your browser by entering the URL in the address bar.
If you are not prompted to download the DLL (e.g. you receive a 404 resource cannot be found error), then confirm the DLL was properly deployed and in the expected path.
If the DLL is in the proper path but you cannot download it, when using IIS 6/Windows 2003 or higher, make sure your application has the Scripts and Executables configuration option enabled. If the option is not selected then IIS will not download the ImageMan.Twain.dll file to the web client.
2. Check to see if the license file is downloadable by navigating to the DTI.ImageMan.Twain.dll.lic
If you cannot download the LIC file (e.g. you receive a 404 resource cannot be found error), please check to see if it is in the same directory as DTI.ImageMan.Twain.dll.
Check that the file is named correctly (DTI.ImageMan.Twain.dll.lic)
If the LIC file is in the proper path but you cannot download it, when using IIS 6/Windows 2003 or higher, make sure your application has the Scripts and Executables configuration option enabled.
3. Make sure the server url in the license file is correct by opening the file in a text editor and confirm the file contains the same domain name or IP that you are using to run the application.
4. If you are running IIS6/Windows 2003 or higher make sure to add the LIC file extension to the known MIME types in IIS using the steps outlined in the help topic entitled Web Application Configuration in IIS6 or IIS7
5. In .Net 2.0 or 3.5 web applications, .Net Framework security configuration will not allow the controls to be instantiated in Internet Explorer. To learn how to modify the security settings, please refer to the section called Modifying the Client .Net Framework Security Settings in the Using the Controls in Internet Explorer topic.
6. In Internet Explorer make sure you have enabled .Net components to run in the browser. Also try adding the website you are running into the 'Local Intranet' to allow the components to run.
You must make sure that your client's computers have either .Net 2.0 or .Net 3.5 framework installed. ImageMan.Net Twain components will not work on a client with only .Net 4.0 installed.
Due to restrictions in the .Net 4.0 code access security model, you must target the .Net 2.0 assembly that ship with ImageMan.Net Twain when building server side code for web applications.