Invalid grant - cannot access api

[LKRPL]

Hi,
we have the following error: 

Exception in thread "main" 
com.google.api.ads.common.lib.exception.OAuthException: Credential could 
not be refreshed.
at 
com.google.api.ads.common.lib.auth.OfflineCredentials.generateCredential(OfflineCredentials.java:178)
at it.reply.fcadda.ForecastGenerator.GetCampaigns.main(GetCampaigns.java:46)
Caused by: com.google.api.client.auth.oauth2.TokenResponseException: 400 
Bad Request
{
  "error" : "invalid_grant"
}
at 
com.google.api.client.auth.oauth2.TokenResponseException.from(TokenResponseException.java:105)
at 
com.google.api.client.auth.oauth2.TokenRequest.executeUnparsed(TokenRequest.java:287)
at 
com.google.api.client.auth.oauth2.TokenRequest.execute(TokenRequest.java:307)
at 
com.google.api.client.auth.oauth2.Credential.executeRefreshToken(Credential.java:570)
at 
com.google.api.client.googleapis.auth.oauth2.GoogleCredential.executeRefreshToken(GoogleCredential.java:362)
at 
com.google.api.client.auth.oauth2.Credential.refreshToken(Credential.java:489)
at 
com.google.api.ads.common.lib.auth.OAuth2Helper.callRefreshToken(OAuth2Helper.java:69)
at 
com.google.api.ads.common.lib.auth.OfflineCredentials.generateCredential(OfflineCredentials.java:172)

-The code here: 
"https://developers.google.com/adwords/api/docs/samples/java/optimization#estimate-keyword-traffic";
-Ads.properties details: 
a) clientId and clientSecret (associated to this account) 
b) clientCustomerId: account created by a test account
c) developerToken (associated to this account)
d) refreshToken (obtained following 
this:"https://github.com/googleads/googleads-java-lib/wiki/API-access-using-own-credentials-(installed-application-flow)#step-2---setting-up-the-client-library"
 
through the test account).

Can you help us? Thanks.

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Re: Invalid grant - cannot access api

['Peter Oliquino' via AdWords API Forum]

Hi,

The "invalid_grant" error usually indicates that the access or refresh 
token being passed in your request is incorrect or invalid. Before 
proceeding further, could you first confirm if you are indeed using a test 
account 

 to 
estimate keyword traffic? If yes, could you also confirm if you created the 
OAuth2 
credentials 
 while 
logged in to the email address associated to your test MCC account? If not, 
please 
do so and generate a new refresh token then retry your request. Let me know 
if the issue persists.

Thanks and regards,
Peter
AdWords API Team

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Also find us on our blog and Google+:
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https://plus.google.com/+GoogleAdsDevelopers/posts
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