403 Forbidden error calling Adwords API

[b...@venturestreet.com]

We deployed an application last month that makes AdWords API calls and it worked just fine a month ago.  Upon using it for the first time in 3 weeks, every API call fails with a 403 Forbidden error.  Nothing has changed in our production environment.  In fact, I can still successfully make API calls from the development environment.  I have redeployed and still get 403 errors.  I have checked and double checked all web.config API values and they are identical in both environments.  Any help would be greatly appreciated.  I am at a dead end.  

Exception: The request failed with HTTP status 403: Forbidden.

Stack trace:

at System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(SoapClientMessage message, WebResponse response, Stream responseStream, Boolean asyncCall) 

at System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(String methodName, Object[] parameters) 

at Google.Api.Ads.Common.Lib.AdsSoapClient.MakeApiCall(String methodName, Object[] parameters) 

at Google.Api.Ads.Common.Lib.AdsSoapClient.Invoke(String methodName, Object[] parameters) 

at Google.Api.Ads.AdWords.v201409.CampaignCriterionService.get(Selector serviceSelector) 

at campaign_map.SetGeos(AdWordsUser& user, Int64 campaignId)

[Josh Radcliff (AdWords API Team)]

Hi,

Have you tried opening a browser on your production server and logging into your account?

Also, is your production server going through a proxy? Have you tried issuing a simple curl get against the AdWords API endpoints to see if it succeeds on your prod server?

Thanks,

Josh, AdWords API Team