VerifyEntitlementToken didn't work

After March 31 2016, we can't validate add-in license via VerifyEntitlementToken.

Received rawXmlToken:
<r v=\"1\"><t aid=\"777777\" pid=\"541e10e6-21de-4d8d-ade0-046e2aac86df\" cid=\"FEBD26988041D138\" did=\"{DB883B0C-955D-4BD9-A584-2D79D657F35D}\" ts=\"2\" et=\"Paid\" ad=\"2016-04-01T13:32:25Z\" ed=\"2029-01-01T00:00:00\" sd=\"2016-04-01\" te=\"2016-05-03T07:24:00\" ss=\"1\" /><d>U2ouyCcfCy17zO1KgUeC12DuwXjgS3NKfzjOTVIJHPY=</d></r>

VerificationServiceClient service = null;
            VerifyEntitlementTokenResponse result = null;
            VerifyEntitlementTokenRequest request = new VerifyEntitlementTokenRequest();
            request.EntitlementToken = rawLicenseToken;
            service = new VerificationServiceClient();
            result = service.VerifyEntitlementToken(request);

[custom.development]