Critical CSS generation fails on some pages
Critical CSS generation fails with unexpected or JavaScript errors on some pages, and speed scores won't load.
Tier II · Emerging Problems that are still building up.
4 public reports · first reported 6 August 2025 · last reported 6 August 2026
What's going wrong
Owners of sites with custom templates, cornerstone pages and admin settings screens report that generating critical CSS in Jetpack Boost stops with a generic unexpected error or a JavaScript error about an undefined value.
AI-assisted: written with the help of AI from the reports. The idea report has the full summary.
In the idea report
- The full summary.
- The products the 4 reports are about, and how many came each month.
- Related problems.
No business has been found with this problem yet, so the report has no contacts. All sales are final — no refunds. Pricing.