When uploading the wasm binary, as a compiled smart contract on the 'ink-workshop' - the canvas-ui that I am running just errors.

Canvas-ui error:

Uncaught error. Something went wrong with the query and rendering of this component. 
Cannot read properties of undefined (reading 'args')

enter image description here

Step: 'Drag the flipper.contract file that contains the bundled wasm blob....'

The Github issues section associated is read-only, hence why I am posting here. Anyone know what might be the problem here?

  • 1
    @NukeManDan as requested.
    – Losko
    Feb 10, 2022 at 8:50
  • Thanks for cross posting!
    – Nuke
    Feb 10, 2022 at 16:54

1 Answer 1


There was an update to the metadata format of a contract (part of the .contract file). The Canvas UI referenced in the tutorial wasn't updated to handle this. Reason for that is that it is soon to be replaced by Contracts UI.

In the meantime you should use the Developer -> Contracts tab of Polkadot.js Apps to interact with your contracts. You can use the sidebar on the top left to connect to a local node 1.

Screenshot of Polkadot.js Apps

  • I'm using Polkadot.js Apps for interacting with Rococo Canvas chain for now to avoid above issue. However, App UI has no reaction when clicking Read button for calling Read methods (for example, totalSupply() of my PSP22Token contract). Execute methods works. Does anyone face with the same situation?
    – Shunsuke
    Feb 10, 2022 at 16:55

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