First, it's important to clarify the goal. You can add the MCP2515 to your schematic in two distinct ways, and it's crucial to know which one you need:
C:\ProgramData\Labcenter Electronics\Proteus 8 Professional\Data\LIBRARY Proteus 7.x: mcp2515 proteus library link
However, this doesn't mean your project must stop. Proteus is a flexible tool, and you have three reliable paths forward: using the native component as a schematic placeholder, importing a full simulation model, or building your own. First, it's important to clarify the goal
Navigate back to the main directory and open the folder. importing a full simulation model
: The MCP2515 handles the data link layer but requires a transceiver for the physical layer. Pick and place an MCP2551 or TJA1050 transceiver model alongside it.