Adobe Reader DC blocks XLSM how do I disable that

Problem

Received a PDF file with embedded Excel attachments, but Adobe Reader does not allow me to open them.

Cause

Adobe security settings block opening Excel files (especially XLSM).

Solution

You have to fix it via registry:

1. Open regedit
2. Navigate to HKLM\SOFTWARE\Policies\Adobe\Adobe Rreader\DC\FeatureLockdown\cDefaultLaunchAttachmentPerms
3. Double click the key labeled tBuiltInPermList
4. Append the following to the end: |.xlsm:2|.xlsx:2|.xls:2

Make sure each extension is listed only once or it might not work. It might be a good idea to copy and paste the entire list into notepad and edit it there.