Template References to offline SharePoint On-Prem Server

lzetaruk​  The issue you described with SP2016 on‑prem is a well‑known behavior. When Word documents are created from templates stored in your old SharePoint 2016 environment, the full path to the template file is embedded in the document. After you shut down the 2016 server, Word still tries to resolve that path each time the document is opened. Because the server no longer exists, Word attempts to connect, times out, and then finally opens the document. That’s why you see the delay.

The resolution is to update or remove those embedded template references. You can do this manually by re‑attaching the document to a valid template in Word (via the Developer tab or Options > Add‑Ins > Templates) or use PowerShell scripts that scan for the AttachedTemplate property and replace the old server path with the new SharePoint Online library path.

To identify affected files, you can either check manually in Word (Developer tab > Document Template) or run a script to flag any documents that still reference http://oldSP2016/.... Files that take unusually long to open are also a strong indicator.

Here are few articles which might help:

• Using Documents after a Server Move (Microsoft Word)
• How to fix slow opening Microsoft Word documents because of invalid network paths
• Updating Many Template References (Microsoft Word)

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