File or assembly not found

Problem

You received the following error message:

Could not load file or assembly "System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" or one of its dependencies. The system cannot find the file specified.

Instead of "System.Web..." you may see another component named here instead.

Solution

Either there's a defect in the .NET Framework installation or an incorrect DLL was installed.

First, repair the .NET installation.

If that doesn't help, check under https://supportdetails.com if you're using the 32-bit or 64-bit version of Windows.

If the 64-bit version of Windows is installed on your computer, copy the file
C:\Program Files (x86)\Citavi 6\bin\PDFNet\x64\PDFNet.dll
to the folder
C:\Program Files (x86)\Citavi 6\bin\
If the 32-bit version of Windows is installed on your computer, copy the file
C:\Program Files (x86)\Citavi 6\bin\PDFNet\x86\PDFNet.dll
to the folder
C:\Program Files (x86)\Citavi 6\bin\