Hi Vasilis,
Thank you for your Suggestion.
Now, Web dispatcher is installed successfully but I still get the same error result. It seems to be something is missing in Web dispatcher configuration. According to your below suggested reference guide, in page 23, it says, To enable HTTPS for Web Dispatcher, make sure that you have sapcrypto.dll file installed already.
https://fioriapps-rds.dispatcher.hana.ondemand.com/docu/EE0_NWG20_BB_ConfigGuide_EN_XX.pdf
Actually, I don't have this sapcrypto file. Is it mandatory to have it? Orelse, are there any other reasons for cause of this issue?
Best regards,
Sreenu