Theme switch breaks on WordPress 6.4 and later
Switching themes on WordPress 6.4 or later triggers redeclare fatal errors or loads the wrong header and footer.
Tier II · Emerging Problems that are still building up.
3 public reports · first reported 11 November 2023 · last reported 24 November 2023
What's going wrong
Several site owners found that after WordPress 6.4 switching a theme caused fatal Cannot redeclare errors, because both the live theme and the switched theme defined the same functions.
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 3 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.