Ever since Microsoft OneDrive updated to Version 2017 (Build 17.3.7059.0930), all my PDF files that I have stored show thumbnails which never happened before. Great.

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However, all my ICO (*.ico) files no longer show thumbnails after they are synched like they used to. Here is a screenshot I took showing the new icons I saved yesterday (which haven't been synched) and older ones that are synched.

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How do I get my icon thumbnails back?

What I've already done:

  1. Rebuild icon cache (Go to C:\Users\<your username>\AppData\Local\Microsoft\Windows\Explorer; delete all iconcache_*.db files)
  2. Icrease size of icon cache (Regedit; KEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer; New String Value "Max cached icons"; Set to 8MB "8192")