NM: Decryption error - You must supply the bulk decryption key in order to extract this file obje (B188671)

Issue
We were able to detect a rare case of broken document when preparing database for migration. We are
using 'non-windows' and combined messages to decrypt mail and prepare user folders.
In some cases the decryption results in documents which are broken. Inline
images are usually collapsed into attachments and all but one are
encrypted and inaccessible even for user. When user tries to open affected
message he gets this error:

You must supply the bulk decryption key in order to extract this file object. Could not save to file

This problem is very rare, only some messages are causing us problems. As
far as we were able to detect this problem is specific only for sent items.

Cause

Running the non-windows version of the decrypt button

Solution

There is a limitation regarding how Notes/Domino handles decryption of sent items This has been resolved using an API. This fix is within the "Migration Message - Windows Decrypt Encrypted Items" button, but is not within the Combined, and non-windows decrypt solutions. This fix uses an API to run the decrypt process. A non-windows operating system cannot use this button since the OS cannot run an API. Unfortunately we could not resolve this issue without using an API, so this issue will affect MAC users.

The workaround is to identify the MAC users, have them either run the "Migration Message - Windows Decrypt Encrypted Items" on a Windows OS, or have them send you their ID and password, and you or another administrator run the decrypt process for them.