Prior to SICStus Prolog 4.3.2, the PrologBeans .NET library depended on J# in order to compile and run the Java version as .NET code. This meant that you needed to link with the Microsoft J# support library, which has been discontinued by Microsoft.
The new C# version is expected to be, mostly, binary compatible with code that use the old J# version. This means that you should be able to use your .NET code with the latest prologbeans.dll even without recompiling your code. You should remove the use of the Microsoft J# library, but that should not be strictly necessary.
If, for some reason, you still need the J# version of the DLL, it is available as bin/prologbeansjsharp.dll) (the C# version is available as bin/prologbeanscsharp.dll) and you can use it with the new name, or rename it, as needed.
Please note: The J# version of PrologBeans is deprecated as of SICStus Prolog 4.3.2, and will be removed in the next patch release.