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.
Please make sure you also have the latest Visual C++ 2005 Runtime. You can get it here.
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).