To use ERPConnect you need also the following SAP libraries.
The classic librfc32.dll assemblies
Please copy the 64-bit version of librfc32.dll in the \System32 folder. You can find the 64-bit version of librfc32.dll in the SAPNet download area.
The 32-Bit Version has to be copied in the \SysWoW64 folder.
Note that the files have the same file name, only the file size varies.
Download the lastest Visual C++ 2005 Runtime.
The exception for wrong or not available librfc32.dlls:
ERPConnect.ERPException: Cannot access librfc32.dll.Please put a 64-bit version of librfc32.dll in your System32 folder (typically C:\Windows\System32) and a 32-bit version of librfc32.dll in your SysWow64 folder (typically C:\Windows\SysWow64).