snarkJS: Error: Scalar size does not match

[nihaoqingtuan]

No description provided.

[mostwanted7]

Probably too many outputs (signal c size), try reducing. But I have this error and I only have a couple of outputs so... Very strange bug

[vinhtrand8]

I got the same error and then I tried to debug snarkjs. I found the problem caused by ffjavascript libraby, this code in buildMultiexp > _multiExp function in ffjavascript/build/main.cjs:

const nPoints = Math.floor(buffBases.byteLength / sGIn);
const sScalar = Math.floor(buffScalars.byteLength / nPoints);

They don't check condition when nPoints is 0, so sScalar will become NaN.
I've fixed it by add this code:

const nPoints = Math.floor(buffBases.byteLength / sGIn);

if (nPoints == 0) return G.zero; // add new here

const sScalar = Math.floor(buffScalars.byteLength / nPoints);