When you Shell-protected a .NET program, DinkeyAdd creates a Dll called XXX.dp32.dll or XXX.dp64.dll (where XXX is the name of your protected program.

Error 544 indicates that this dll file is not the expected file for your protected program. i.e. it is not the dll file that was created when your protected program was created.

The most likely explanation for this is that the dll file still exists from a previous time you protected your software. For example, you might be testing your software by installing it onto a machine. If you recompile your software, re-protect it and then re-install it, the dll file may not be updated by the installer because it will have the same version number. So you will be using the new protected program with a previous dll file. In this case you should modify the installer to force the installation of this dll file.