First, ensure that the Blackbaud application client is installed on the same machine. If it's already installed and the steps below do not apply, then uninstall and re-install the client application.

The program must be modified to run in a 64-bit environment.  Open the solution file in MS Visual Studio (steps may differ depending on the VS version installed) and complete the following steps:
  1. Go to the Project menu and select [Project_Name], Properties
  2. In the Build tab, change the Target Platform from Any CPU to x86
  3. Recompile the customization
NOTE: For Raiser's Edge, this issue is resolved in 7.96, patch 13, planned for release in September - October 2018.