When installing GpgOL 2.5.4 (by Gpg4Win 3.1.24), and doing a test for mail-encryption on Windows 10 x64 21H2 <=> 20H2 (HTML- or Plaintext), Outlook shows no mail-body and no trust-state (see image, on top right corner):
When replacing the original gpgol.dll from Gpg4Win 3.1.16 or doing a reinstall of Gpg4Win 3.1.16 or 3.1.23, everything works fine (correct paring and decoding):
The error occurs, when using GpgOL 2.5.4 (from the Gpg4Win 3.1.24-Build); when using GpgOL from 3.1.16 or 3.1.23, NO ERROR occurs.
On both machines, we're using Outlook (18.104.22.16857.1000) MSO (16.0.5361.1000) 64Bit
To reproduce the error, we only have to replace directly the "gpgol.dll" in their corresponding directories.
Here is the (i hope so) disarmed gpgol.log.txt (i hope, i have removed all sensitive data):