Update from Svelte 5.43.3 to latest one (5.43.10) causing freezes on load data re-render (#each)

[p0xz]

Describe the bug

When my data gets rendered and it contains animate:flip it's causing this error:
Invalid keyframe value for property transform: matrix(1, 0, 0, 1, 0, 18) translate(NaNpx, NaNpx) scale(NaN, NaN)

Here's the repo:
https://github.com/p0xz/BossFlix-Moviesite/blob/Experimental/src/routes/%2Bpage.svelte

It actually freezes whole website causing me to not be able to click anywhere and eventually chrome will just asks if i want to wait or shut it off, but even after I removed the animate:flip there's still issue with the freezing. I don't know what's going on under the hood really, but this code wasn't causing issues in the Svelte 5.43.3

PS: Never written an issue on gh, so sorry if my description sounds awful 🗡️

Reproduction

Code used in this issue:
https://github.com/p0xz/BossFlix-Moviesite/blob/Experimental/src/routes/%2Bpage.svelte
https://github.com/p0xz/BossFlix-Moviesite/blob/Experimental/src/routes/%2Blayout.svelte

Logs

450x Invalid keyframe value for property transform: matrix(1, 0, 0, 1, 0, 18) translate(NaNpx, NaNpx) scale(NaN, NaN)

System Info

System:
    OS: Linux 6.14 Ubuntu 24.04.3 LTS 24.04.3 LTS (Noble Numbat)
    CPU: (16) x64 AMD Ryzen 7 5800X 8-Core Processor
    Memory: 20.49 GB / 31.27 GB
    Container: Yes
    Shell: 5.9 - /usr/bin/zsh
  Binaries:
    Node: 25.0.0 - /home/p0xz/.nvm/versions/node/v25.0.0/bin/node
    npm: 11.6.2 - /home/p0xz/.nvm/versions/node/v25.0.0/bin/npm
    bun: 1.3.1 - /home/p0xz/.bun/bin/bun
  Browsers:
    Chrome: 142.0.7444.162
    Firefox: 145.0
    Firefox Developer Edition: 145.0

Severity

blocking an upgrade

[gyzerok]

Can you try 5.43.7 and 5.43.8 to pin the problematic version? I believe it should come from 5.43.8 as we are also experiencing problems there.

This is perhaps related to #17181

[p0xz]

Hi @gyzerok, I tested both versions (5.43.7 & 5.43.8) and yes it's the 5.43.8 causing issues. 0 issues in 5.43.7. Also I've noticed that after removing also transitions (svelte/easing) from my code, it stops freezing. So it looks like all kind of transitions are causing issues on #each block. I haven't had an opportunity to test it thoroughly, but looks like it's tied to #17150 .

[dummdidumm]

Could you check if the latest version (5.43.12+) still shows these issues? This was likely fixed by #17191

[p0xz]

Yep, it fixed the issue also no animate:flip errors everything works fine, thanks!