X.509 certificate cannot be found by WCF service

I have a WCF service hosted in IIS.

Using certmgr.msc I can see my X.509 certificate in Personal -> Certificates but still I get this error:

Cannot find the X.509 certificate using the following search criteria: StoreName 'My', StoreLocation 'CurrentUser', FindType 'FindByThumbprint', FindValue 'b0 5f 3f ...'.

I changed storelocation, find type... but still the same error 开发者_如何学Goappears. I guess IIS cannot use the certificate because of lack of permission.

How can I fix this ?

Right click on the cert, select Manage Private Keys, grant rights to the user under which the IIS app pool is running.