Hi Lilkar,
As per the Viewer error image in earlier thread please refer below KBA and link for your reference
1558691 - Error: The viewer could not process an event. Failed to open the connection.
https://service.sap.com/sap/support/notes/1558691
Link:-
connection error when viewing crystal report on... | SCN
http://www.crystalreportsbook.com/forum/forum_posts.asp?TID=19810
Thanks,
Daya