[Bug] Firefox site storage inconsistency prevents initialization: AboutUI is not defined

PairDrop failed to initialize on the official https://pairdrop.net instance in my existing Firefox profile.

The problem is now resolved and I cannot reproduce it after clearing PairDrop's Firefox cache/site storage.

I am reporting it primarily for searchability and in case similar reports appear. I do not expect immediate action if there is not enough information to investigate it.

What happened

When opening https://pairdrop.net, initialization stopped with:

Uncaught (in promise) ReferenceError: AboutUI is not defined
    hydrate https://pairdrop.net/scripts/main.js:168
    initialize https://pairdrop.net/scripts/main.js:64
    PairDrop https://pairdrop.net/scripts/main.js:35
    <anonymous> https://pairdrop.net/scripts/main.js:241

Immediately before the exception, the console reported that all deferred assets, including ui.js, had loaded:

Load deferred assets...
Script loaded successfully: scripts/browser-tabs-connector.js
Script loaded successfully: scripts/util.js
Script loaded successfully: scripts/network.js
Stylesheet loaded successfully: styles/styles-deferred.css
Script loaded successfully: scripts/ui.js
Script loaded successfully: scripts/libs/qr-code.min.js
Script loaded successfully: scripts/libs/zip.min.js
Script loaded successfully: scripts/libs/no-sleep.min.js
Script loaded successfully: scripts/libs/heic2any.min.js
Loading of deferred assets completed.
Hydrate UI...
Uncaught (in promise) ReferenceError: AboutUI is not defined

Reloading the page did not fix it.

I only have uBlock Origin installed. Disabling uBlock Origin did not change the behavior.

Resolution

Clearing PairDrop's cache/site storage in Firefox and reopening the site fixed the problem immediately.

PairDrop now works normally in Firefox, so unfortunately I can no longer inspect the problematic cached responses.

Environment

• Instance: official https://pairdrop.net
• Operating system: macOS 26.5.2 (25F84) Apple Silicon M1
• Firefox: 152.0.6 (aarch64)
• Extensions: uBlock Origin, also tested disabled
• PairDrop version: v1.11.2

Possible explanation

This may have been an inconsistent set of browser or service-worker-cached assets.

main.js attempted to instantiate AboutUI, while the executed ui.js apparently did not define it, despite its script load event succeeding.

Clearing the stored site data fixing the problem supports a cache or service-worker-state explanation, but I cannot confirm the exact cause.

I found #384, which also involved service-worker caching, but that issue appears different because it concerned a self-hosted v1.11.0 instance behind Nginx and affected different browsers.

Please feel free to close this as non-reproducible if there is not enough information.