Hashlips Engine gives error after generating 1 image and NO Metadata is generated

Question

I am not able to generate any metadata in Hashlips engine and it stops after building 1 image. Looked around a lot of solutions but nothing seems to rectify.

I am getting this error :

UnhandledPromiseRejectionWarning: TypeError [ERR_INVALID_ARG_TYPE]: The "data" argument must be of type string or an instance of Buffer, TypedArray, or DataView. Received undefined

The error is shown on these lines:

const writeMetaData = (_data) => {
fs.writeFileSync(${buildDir}/json/_metadata.json, _data);
};

fs.writeFileSync(
${buildDir}/json/${_editionCount}.json,
JSON.stringify(metadata, null, 2)
);

saveMetaDataSingleFile(abstractedIndexes[0]);

Node:v14.21.3 NPM:6.14.18

Any help is appreciated!! Many thanks