How to fix InDesign 2026 Layout UI plug-in error

Adobe resolved the InDesign Server 2026 compatibility issues introduced in v21.1 and v21.2 with the release of v21.3. Typefi Server 8.20 and later supports InDesign Server 2026 (v21.3 or later). Before making any changes to InDesign templates, make sure your InDesign desktop is also updated to v21.3 or later. 

If you saved any InDesign documents in v21.2, those documents still need to be cleaned before InDesign Server can process them. See the steps below. 

The problem

Adobe InDesign 2026 (v21.2) mistakenly tagged a desktop-only plug-in (Layout UI) as "Required". When attempting to use an affected document with InDesign Server 2026, the workflow will fail with this error:

[Error [server] The document "<name>" uses one or more plug-ins which are not currently available on your system. Layout UI.InDesignPlugin

The fix

If you are on v21.1 or v21.2, update your InDesign desktop to v21.3 or later before editing any templates.

If you have already saved InDesign documents using v21.2, you must clean each affected document to restore compatibility: 

1. Export affected documents to InDesign Markup (IDML).
2. Open the IDML files in InDesign 2026 v21.3 or later.
3. Use File → Save As to save the file as an InDesign document, overwriting the original. This restores InDesign Server 2026 compatibility.