When the NoMachine package for 64bit is downloaded from Firefox and the executable is launched from the Downloads list, the setup raises an 'Entry point not found' dialog for the libssl library like:

"Cannot find an entry point for ... in library C:\Program Files\NoMachine\bin\libssh.dll”

Steps to reproduce:
1) Access the download page from the NoMachine web site https://www.nomachine.com
2) Click on the "Download Now" button and download the package ( .exe file )
3) Double click on the .exe file from "Downloads" window/dialog to launch the executable

As a workaround, launch the NoMachine setup by clicking on the .exe file from the Windows explorer. 

The described behaviour is strictly related to how Firefox handles the executable, in particular we found that it sets the 'PreferSystem32Images' flag before running the .exe application. This makes the system link to the system libssl instead of the NoMachine libssl library sported by the package. As a consequence the 'Entry point not found' message is triggered.

As a reference, this is the bug report reported to Firefox: https://bugzilla.mozilla.org/show_bug.cgi?id=1802834