Connect a (+12V) to the VCC pin of the L298 module.

If you downloaded from an untrusted aggregator site, the file might be corrupt or incomplete. Try downloading directly from The Engineering Projects or the GitHub mirror instead. The Engineering Projects library is tested and confirmed to work with Proteus 7 and Proteus 8.

The dedicated L298 library provides a VSM (Virtual System Modeling) component that reacts accurately to microcontrollers like Arduino, PIC, or 8051.