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Cannot preview txt and html email attachments in Outlook 2019 x64
Hello, when I try to preview a txt or html attachment in Outlook 2019 x64 (on Win 10 20H2 x64) email I've got an error: This file cannot be previewed because of an error with the following previewe...
Finally I've found the solution (for all extensions having associated preview handlers in registry).
I had 64-bit Preview Handler Surrogate Host registry key missing in HKCR\AppID section, but did have 32-bit version.
So I recreated 64-bit version similarly to 32-bit key.
HKEY_CLASSES_ROOT\AppID\{6d2b5079-2f0b-48dd-ab7f-97cec514d30b}
@="Preview Handler Surrogate Host"
"DllSurrogate"(REG_EXPAND_SZ)="C:\Windows\System32\prevhost.exe"
From that point all the previews in Outlook desktop (2019) and in Preview pane in Windows Explorer started working, no need to restart (Explorer or Windows).