VSI 7.4 on vCenter 6.7U1b

Hi, I deployed VSI 7.4 on vCenter Environment 6.7U1b and I have a problem with installing VSI plugin on this vCenter. When I pass on vCenter information on a SIS Administration web page it's showing that The operation was successful however when I go to vCenter Flash Web Client and to Global Inventory List I cannot find anything related to VSI or SIS. Plugin is visible in http://xxxx/mob/?moid=ExtensionManager&doPath=extensionList. Network ports have been open between vCenter and VSI VM (8443 and 443).

vCenter Server has a custom SSL certificate, I added public SSH key in SIS administration web page.

I'd like to manage RecoverPoints and SRM with VSI but I'm unable to because of this deployment problem, can you help me with this? any advice?