Consume Rest API built based on ASP.NET 4.5

Hi All,

I'm new to Outsystems Platform. I use Outsystems Platform 10 which the personal environment in cloud.

I'd like to consume REST API built using ASP.NET 4.5 because our company has been previously build this API, but when I click Test, it failed with message 'The underlying connection was closed: An unexpected error occurred on a send.'

I try to check Service Center and no log at all.

Is this because the REST API not build using ASP.Net 4.6.1? I refer to this link and there is requirements about that. 

Thanks in advanced.

Hi Jessica,

For consuming a REST API, it really doesn't matter at all how it was built and with which tools. You can consume any REST API, as long as it behaves as expected. The error you mention may be a problem with the secure connection, e.g. expired certificates.

Hi Kilian,

Thanks for your response.

I tried using Postman and it give result as expected.

Is there any error log for Test Consume Rest API? I search in ServiceCenter but there is no log recorded.

Hi Jessica,

Where do you see the error currently, if not in Service Center? Is it caught by an exception handler? If so, is the "Log Error" set to Yes?

Hi Jessica,

You must have error and integration logs for that in Service Center since there is no way to disable error logging for Integration calls. Check the logs carefully, especially since in personals (because it's a shared system) the logs are a bit slow to appear.

As for your error, that message like Killian mentioned is usually then there are problems establishing a HTTS/SSL connection. That being either becuase of bad certificates or ssl version restrictions.

Is your personal environment already upgraded to OutSystems 10? Or is it still a 9.1 environment?

João Rosado

I have questions, its new forum?

Thanks for your response.


Currently I see the response when I test the API in consume REST API Method, like in attachment.


I already look in error logs and integration logs and no log captured with my endpoint url. Am I miss something to be set so I can log the error when I test API like in attachment? 

Yes, I use Outsystems Platform 10. Is there any restriction for SSL version in Outsystems?

Thanks in advanced.

Jessica, it might be there's no error logged because it goes already wrong in Service Studio, rather than in the code itself. But João should be able to clarify this.

EDIT: You said with Postman it works - is Postman running from your workstation? Iirc, Service Studio doesn't directly connect to the REST API but requests the Platform, running on the server, to do this. So there may be some problems in that area.

Hi Jessica,

Right, I was talking about logging in runtime. The "test window" doesn't cause any logs.

Can you just igore the Test and try to call it in runtime? It will give you more information and we can see if it's just a problem of the Test or not.

As for my mention of ssl version limitations. In version 9 there were some limitations by default, due to .NET defaults (read more about it here). But in 10 that should no longer be an issue since the ssl defaults for .NET 4.6.1 already include TLS 1.1 and 1.2.

João Rosado