Problem with Integrating Exchange 2013 CU8 and Skype for B

hi

my exchange server (2013 CU8) was working fine until i changed certificates and replace all of them (even Serve Oauth and WMSvc)  by a new one (Internal CA).

now when i run "new-CspartnerApllication: from Skype for b server im getting this error:

error : cannot bind parametet 'Metadataurl' to the target.....

and when i open  https://xxxxxx/autodiscover/metadata/json/1 using a browser im getting :

Server Error in '/Autodiscover' Application. cold not find any resource appropriate for the specific culture or the neutral culture. ........

Also i can see Exchange frontend HTTP error in Event viewer with Event ID 1003 , 4999 and 1309 warning.

i think certificate is fine , i can open web services without cert error also i can open Autodiscover.xml.

does anyone know whats wrong with my server?

Thanks!