insertFileFromBase64 disables text selection in Word on the web

[NataliaKravcheniaTR]

After calling Body.insertFileFromBase64, text selection in the document becomes unresponsive - the user can no longer select any text in Word on the web.

Your Environment

• Platform [PC desktop, Mac, iOS, Office on the web]: Office on the web
• Host [Excel, Word, PowerPoint, etc.]: Word
• Office version number: 20260623.4
• Operating System: Windows
• Browser (if using Office on the web): Chrome

Expected behavior

After insertFileFromBase64 completes, the user can select text in the document as normal.

Current behavior

After insertFileFromBase64 is called, the user cannot select any text in the document. Selection appears completely unresponsive.

Steps to reproduce

https://gist.github.com/NataliaKravcheniaTR/1ec4a3723e7b599e7d9a14e0fe23926b

1. Load the snippet in Word on the web (Script Lab).
2. Click the Init button.
3. Click the Run button.
4. Try to select any text in the document - selection does not work.

Additional context

• The snippet calls insertFileFromBase64 twice to make the issue reproduce reliably in Script Lab.
• In our application the issue reproduces with a single insertFileFromBase64 call.
• Investigation is ongoing to determine what else may contribute to the issue.

Link to live example(s)

https://gist.github.com/NataliaKravcheniaTR/1ec4a3723e7b599e7d9a14e0fe23926b

[microsoft-github-policy-service]

Thank you for letting us know about this issue. We will take a look shortly. Thanks.

[github-actions]

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