"Sorry, the file .oft couldn't be opened"

M 0 Reputation points
2026-05-12T13:51:55.5533333+00:00

Today, we are unable to open .OFT files:

"Sorry, the file .oft couldn't be opened. There was an error opening the file"

We were able to open OFT files fine yesterday and previously.

Microsoft Outlook Version: 1.2026.428.200

Client Version: 20260501001.13

WebView2 Version: 147.0.3912.98 (Stable)

Outlook | Windows | New Outlook for Windows | For business
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M 0 Reputation points
2026-06-04T16:31:01.67+00:00

Thanks, this appears to have been fixed in the latest version of New Outlook:

Microsoft Outlook Version: 1.2026.520.400

Client Version: 20260529014.10

WebView2 Version: 148.0.3967.96 (Stable)

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  1. M 0 Reputation points
    2026-05-13T10:34:17.6566667+00:00

    Thanks for your reply. I’ve tested this by creating a new OFT file in Classic Outlook and then opening the same file in New Outlook.

    In Classic Outlook, the OFT opens exactly as expected - as a new editable draft ready to modify and send.

    In the New Outlook, however, the OFT opens but none of the fields are editable. It behaves more like a read‑only preview rather than a draft.

    We use a system that generates an OFT order email, and this generated OFT has also stopped working in the New Outlook as of yesterday, with the error the file couldn't be opened. It still opens correctly in Classic Outlook.

    Please see screenshot below.

    Here's a copy of a generated OFT file too (renamed to .oft.txt in order to attach here) Order Email.oft.txt

    Screenshot 2026-05-13 112416 It appears to be a regression in the latest version of New Outlook.

    Thank you

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