I ran into a problem migrating my DataSnap server using encryption on the transport level to Delphi 11 Alexandria. I was able to reproduce the problem in a very simplistic sample project and have logged an issue in the Embarcadero JIRA instance here. Your vote would be appreciated.
So the second project will have to wait until the OpenSSL encryption works again in Delphi 11 Alexandria.
Not sure if this is the actual cause, however the DLLs in the subversion folder are a bit out of date. More recent versions of the OpenSSL files can be found here:
The latest version there is 1.0.2u (I think this is the last ever version on the 1.0.2 branch?). The files in the subversion folder are 1.0.2n