Uncaught TypeError: Cannot read properties of undefined (reading 'lazyPreloaderClass')

[BerkeAras]

Check that this is really a bug

• [x] I confirm

Reproduction link

https://codesandbox.io/p/devbox/swiper-default-forked-6c96g3?workspaceId=ws_NcfeSzfz6N96RJW7VKTnaL

Bug description

We are getting an error Uncaught TypeError: Cannot read properties of undefined (reading 'lazyPreloaderClass').

Due to our complex case (combining VueJS with other technologies) we cannot reproduce the issue.

Expected Behavior

No response

Actual Behavior

No response

Swiper version

11.2.6

Platform/Target and Browser Versions

macOS Arc Browser, same issue on Windows/Linux/iOS/Android and on other browsers too.

Validations

• [x] Follow our Code of Conduct
• [x] Read the docs.
• [x] Check that there isn't already an issue that request the same feature to avoid creating a duplicate.
• [x] Make sure this is a Swiper issue and not a framework-specific issue

Would you like to open a PR for this bug?

• [x] I'm willing to open a PR

[Scribilicious]

Yes, it’s a rare issue. I stumbled upon it as well. Hopefully, they accept your pull request or find another way to fix this issue, since it’s spamming my error log.

[BerkeAras]

Yes, it’s a rare issue. I stumbled upon it as well. Hopefully, they accept your pull request or find another way to fix this issue, since it’s spamming my error log.

Could you find any fix until the PR is merged & released? @Scribilicious

[wikylyu]

I have the exact same problem. I'm using Angular 20 with SSR.

app.config.ts:30  ERROR TypeError: Cannot read properties of undefined (reading 'lazyPreloaderClass')
    at swiper-core.mjs:907:73
    at timer (zone.js:1809:37)
    at _ZoneDelegate.invokeTask (zone.js:431:33)
    at ZoneImpl.runTask (zone.js:161:47)
    at invokeTask (zone.js:515:34)
    at ZoneTask.invoke (zone.js:504:48)
    at data.args.<computed> (zone.js:1778:32)

    "swiper": "^11.2.8",

[wikylyu]

import { register } from 'swiper/element';
register()

register() raise the error.

[mdmontesinos]

I'm also facing this error with Blazor Static SSR with Enhanced Navigation (.NET 9)