gorhill/uBlock · error · Error

Failed to initialize public suffix list.

Error message

Failed to initialize public suffix list.

What it means

StaticNetFilteringEngine.create() initializes the Public Suffix List unless you pass { noPSL: true } (index.js:267). pslInit() (index.js:87) first tries a serialized snapshot at build/publicsuffixlist.json, then falls back to the raw asset assets/thirdparties/publicsuffix.org/list/effective_tld_names.dat; if both are unavailable or empty it returns undefined and create() throws. The PSL is required so the engine can reason about domains and TLDs for network filtering.

Solutions

1. If you do not need PSL-based matching, create the engine with `{ noPSL: true }`.
2. Ensure build/publicsuffixlist.json is present by running the package's build step (e.g. `npm run build`) before calling create().
3. Supply your own PSL data by calling the exported pslInit(rawString) with a non-empty string BEFORE create(); pslInit parses and caches it (index.js:88-90).
4. Confirm that assets/thirdparties/publicsuffix.org/list/effective_tld_names.dat ships with your deployment.

Example fix

// before
const engine = await StaticNetFilteringEngine.create(); // throws if PSL data missing

// after (option A: opt out)
const engine = await StaticNetFilteringEngine.create({ noPSL: true });

// after (option B: supply PSL yourself)
import { StaticNetFilteringEngine, pslInit } from 'uBlock'; // exported index.js:291-295
pslInit(myPslText);               // parsed & cached when non-empty
const engine = await StaticNetFilteringEngine.create();

import { existsSync } from 'fs';
import { resolve } from 'path';

// Probe the two sources pslInit() tries (index.js:97 and index.js:109-112).
const snapshot = resolve(pkgRoot, 'build/publicsuffixlist.json');
const rawList = resolve(pkgRoot, 'assets/thirdparties/publicsuffix.org/list/effective_tld_names.dat');
const pslAvailable = existsSync(snapshot) || existsSync(rawList);

const engine = await StaticNetFilteringEngine.create(
  pslAvailable ? {} : { noPSL: true }
);

let engine;
try {
  engine = await StaticNetFilteringEngine.create();
} catch (err) {
  if (err && /public suffix list/i.test(err.message)) {
    // Fall back to no-PSL mode only if you can tolerate reduced domain reasoning.
    engine = await StaticNetFilteringEngine.create({ noPSL: true });
  } else {
    throw err;
  }
}

When it happens

Trigger: Calling create() (or create({})) when build/publicsuffixlist.json is absent AND the effective_tld_names.dat asset is missing or empty. Importing the module from a bundle that excluded the JSON/data files. Running from a source checkout before the build step generates build/publicsuffixlist.json.

Common situations: Bundling with webpack/rollup in a way that drops the package's build/ or assets/ directories; deploying only the JS without the PSL data; a truncated or corrupt effective_tld_names.dat file; fresh source checkout with `npm run build` not yet run.

Related errors

• Only a single instance is supported.
• Pending useLists() operation

AI-assisted analysis of gorhill/uBlock@c68df492fd (2026-08-12). Data as JSON: /api/errors/b7db5ef6e873c861. Report an issue: GitHub.

Appendix: source

Thrown at platform/nodejs/index.js:268

    compileList(...args) {
        return compileList(...args);
    }

    async serialize() {
        const data = snfe.serialize();
        return s14e.serialize(data, { compress: true });
    }

    async deserialize(serialized) {
        const data = s14e.deserialize(serialized);
        return snfe.unserialize(data);
    }

    static async create({ noPSL = false } = {}) {
        const instance = new StaticNetFilteringEngine();

        if ( noPSL !== true && !pslInit() ) {
            throw new Error('Failed to initialize public suffix list.');
        }

        return instance;
    }

    static async release() {
        if ( snfeProxyInstance === null ) { return; }
        snfeProxyInstance = null;
        await useLists([]);
    }
}

/******************************************************************************/

// rollup.js needs module.exports to be set back to the local exports object.
// This is because some of the code (e.g. publicsuffixlist.js) sets
// module.exports. Once all included files are written like ES modules, using
// export statements, this should no longer be necessary.

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