Do NOT use libssl-1_1-x64.dll or any DLL with version numbers in the filename. Indy 9 hardcodes the legacy names ( libeay32 , ssleay32 ).
However, in Indy 9, the easiest "code fix" is often to check the IdSSLOpenSSL.pas unit. Ensure the DLL names are defined correctly: Delphi 7 Indy 9 Could Not Load Ssl Library
Let’s address the solutions in order of complexity: from quickest and easiest to most permanent and robust. Do NOT use libssl-1_1-x64
If you are forced to use modern DLLs for security compliance (not recommended for Indy 9 without heavy modification), you would have to change these constants and recompile the Indy 9 packages, though this usually leads to runtime crashes due to API changes. ssleay32 ). However