I am trying to follow along with a tutorial on youtube. however i keep getting errors when i try to migrate.

This is the error - Error: *** Deployment Failed ***

"MemoryToken" is an abstract contract or an interface and cannot be deployed.

  • Import abstractions into the '.sol' file that uses them instead of deploying them separately.
  • Contracts that inherit an abstraction must implement all its method signatures exactly.
  • A contract that only implements part of an inherited abstraction is also considered abstract.
at Deployer._preFlightCheck (/usr/local/lib/node_modules/truffle/build/webpack:/packages/deployer/src/deployment.js:178:1)
at <anonymous>
at process._tickCallback (internal/process/next_tick.js:118:7)

Truffle v5.1.39 (core: 5.1.39)

  • It is likely the MemoryToken contract requires some function to be implemented and you didn't.
    – Ismael
    Nov 1, 2021 at 5:47

1 Answer 1


I got the same problem. My problem is that I didn't delete the code "is ERC721Full" after "cotract MemoryToken". Because of the inherit of ERC721Full , it makes MemoryToken a abstract contract. if didn't implement the functions, it cant be deployed.

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