Title: API version 2 or lower is deprecated
Last modified: February 13, 2026

---

# API version 2 or lower is deprecated

 *  Resolved [gute](https://wordpress.org/support/users/gute/)
 * (@gute)
 * [2 months ago](https://wordpress.org/support/topic/api-version-2-or-lower-is-deprecated/)
 * Hello,
 * The built-in wordpress Customizer stopped loading due to an API version deprication:
 * Console says:
 * `Block with API version 2 or lower is deprecated since version 6.9. See: https://
   developer.wordpress.org/block-editor/reference-guides/block-api/block-api-versions/
   block-migration-for-iframe-editor-compatibility/ Note: The block "pdfemb/pdf-
   embedder-viewer" is registered with API version 2. This means that the post editor
   may work as a non-iframe editor. Since all editors are planned to work as iframes
   in the future, set the ``apiVersion` field to 3 and test the block inside the
   iframe editor.
 * The front page (loaded by default withing the Customizer) doesn’t contain any
   embedded pdf. Some other pages do.
 * Any solution please?
    - WordPress : v6.9.1
    - PDF Embedder : v4.9.3
    - Theme Astra : v4.12.3

Viewing 2 replies - 1 through 2 (of 2 total)

 *  Plugin Support [Jackson Mwange](https://wordpress.org/support/users/mwangejack/)
 * (@mwangejack)
 * [2 months ago](https://wordpress.org/support/topic/api-version-2-or-lower-is-deprecated/#post-18825012)
 * Hi [@gute](https://wordpress.org/support/users/gute/),
 * Thanks for reaching out to us!
 * It looks like you’ve encountered a conflict between the new WordPress Block API
   standards and the Customizer’s loading sequence.
 * Even though you don’t have a PDF on your homepage, the Customizer loads the ‘
   definitions’ for all your blocks in the background. The warning you see regarding
   API version 2 is WordPress signaling that it wants the plugin to update its code
   for better iframe compatibility. However, this should only be an alert, since
   WordPress 6.9 and above still supports API Version 2 for blocks.
 * That said, to get you back up and running immediately:
    - Please try temporarily deactivating the PDF Embedder plugin. This should allow
      the Customizer to load so you can finish your Astra theme edits.
    - Once your theme changes are saved, you can reactivate the plugin. Your embedded
      PDFs will remain intact.
 * I have also shared this feedback with our team to update the apiVersion field
   to align with the WordPress 6.9+ requirements. We appreciate your patience as
   our team works on this.
 * Please let me know if you have any further questions!
 *  Plugin Support [Jackson Mwange](https://wordpress.org/support/users/mwangejack/)
 * (@mwangejack)
 * [1 month, 4 weeks ago](https://wordpress.org/support/topic/api-version-2-or-lower-is-deprecated/#post-18828695)
 * Hi [@gute](https://wordpress.org/support/users/gute/) ,
 * We haven’t heard back from you in a few days, so I’m going to go ahead and close
   this thread for now. But if you’d like us to assist further, please feel welcome
   to continue the conversation.
 * Thanks!

Viewing 2 replies - 1 through 2 (of 2 total)

You must be [logged in](https://login.wordpress.org/?redirect_to=https%3A%2F%2Fwordpress.org%2Fsupport%2Ftopic%2Fapi-version-2-or-lower-is-deprecated%2F%3Foutput_format%3Dmd&locale=en_US)
to reply to this topic.

 * ![](https://ps.w.org/pdf-embedder/assets/icon.svg?rev=3227003)
 * [PDF Embedder](https://wordpress.org/plugins/pdf-embedder/)
 * [Frequently Asked Questions](https://wordpress.org/plugins/pdf-embedder/#faq)
 * [Support Threads](https://wordpress.org/support/plugin/pdf-embedder/)
 * [Active Topics](https://wordpress.org/support/plugin/pdf-embedder/active/)
 * [Unresolved Topics](https://wordpress.org/support/plugin/pdf-embedder/unresolved/)
 * [Reviews](https://wordpress.org/support/plugin/pdf-embedder/reviews/)

## Tags

 * [api](https://wordpress.org/support/topic-tag/api/)
 * [customizer](https://wordpress.org/support/topic-tag/customizer/)

 * 2 replies
 * 2 participants
 * Last reply from: [Jackson Mwange](https://wordpress.org/support/users/mwangejack/)
 * Last activity: [1 month, 4 weeks ago](https://wordpress.org/support/topic/api-version-2-or-lower-is-deprecated/#post-18828695)
 * Status: resolved