WinRAR SFX (aka our Samba package) user interface broken in recent trunk builds

The UI of WinRAR SFX packages is broken in r74613. It worked fine in the 0.4.4-CLT2017 release (r74129).
This severely affects our custom Samba package: In particular, the explanation text box is entirely missing and the default destination path is set to C:\ReactOS\system32 instead of C:\Program Files\samba. Because people don't know that the Samba package MUST be installed into "Program Files" and the default destination is wrong, Office 2010 cannot be installed right now.

My screenshot should show it all.