This issue occurs when you try to execute B4D.jar with java 64-bit. Because jpcap.dll have been built for 32-bit architectures, B4D had to be built for 32-bit architectures as well.

Please install java 32-bit try again.

To temporary fixed this issue :

• Open a terminal.
• Navigate to the B4D.jar folder using cd C:\path\to\B4D\folder
• Type "C:\full\path\to\java32\bin\java.exe" -jar B4D.jar