OpenUTAU freezes whenever rendering on Linux

[RichardKanshen]

Acknowledgement

• I have read Getting-Started and FAQ
• If dealing with version 0.1.549 or higher, you have installed the .NET 8 runtime

🐛 Describe the bug

Whenever OpenUTAU is rendering notes, the entire UI becomes unresponsive until the rendering finishes, which includes ignoring all user input.
This appears to be a caching issue, as clearing the cache fixes the issue temporarily, but after even a couple of edits the cache builds up again and starts freezing again.

Explains how to reproduce the bug

1. Open a project with multiple tracks, each containing some notes
2. OpenUTAU attempts to render all tracks, seemingly synchronously, ignoring any user interaction while it does so
3. Changing any note causes a re-render of all notes on every track, causing the freeze again

OS & Version

Linux 6.17.9-arch1-1 (Released on November 24 2025)

Logs

N/A (not causing a crash)

[BagelHero]

The log is generated regardless of a crash and may expose any potential reading or writing errors, but it's true that it likely doesn't so I won't push for it.

Can you confirm which OpenUtau version you're using?

[RichardKanshen]

v0.1.567.0, updated from an earlier version manually because auto-update appears to be broken