Exception "Request failed: The server committed a protocol violation. Section=ResponseStatusLine" with multi-step availability test

_This issue has been moved from [a ticket on Developer Community](https://developercommunity2.visualstudio.com/t/Exception-Request-failed:-The-server-co/1278145)._

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Hi,

we have a problem with a multi-step availability test both on Visual Studio 2019 Enterprise and Azure Application Insights.

The first HTTP request works as expected, but the second HTTP request ends with the following exception:

Request failed: The server committed a protocol violation. Section=ResponseStatusLine

I have done the following tests trying to find a solution to this issue:

1) Tested the same HTTP requests flow with Postman and they works fine;
2) Tested the same HTTP requests flow with cURL and they works fine;
3) Tested the same HTTP requests flow with Visual Studio 2019 Enterprise as a webtest project and got the same exception at the second HTTP request call. If i use Fiddler or Burp in the middle of the HTTP calls, I don't get any exception and also the Visual Studio 2019 webtest project run works fine. I managed also (without any proxy in behind) to temporarily use a TLS cipher that permits Wireshark decryption with the private key of the HTTPS server SSL certificate (by temporarily disabling all ciphers that supports the Diffie-Hellman key exchange) and checked the trace of the HTTP requests, but I haven't find any useful information, the HTTP flow seems correct at first glance (HTTP headers are corrects , and also JSON data returned and HTTP status).

Have you any suggestion on how I can better investigate the reason behind this exception?

Just to add another information, we are currently using Dynatrace Synthetic with the same HTTP flow and it works fine, and we are trying to configure Azure Application Insights with the same services in order to evaluate if we can switch from Dynatrace to Azure Application Insights.

Thanks in advance for all your replies!

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### Original Comments

#### Feedback Bot on 12/6/2020, 06:23 PM:

We have directed your feedback to the appropriate engineering team for further evaluation. The team will review the feedback and notify you about the next steps.

#### Feedback Bot on 12/6/2020, 06:52 PM:

Thank you for sharing your feedback! Our teams prioritize action on product issues with broad customer impact. See details at: https://docs.microsoft.com/en-us/visualstudio/ide/report-a-problem?view=vs-2019#faq. In case you need answers to common questions or need assisted support, be sure to use https://visualstudio.microsoft.com/vs/support/. We’ll keep you posted on any updates to this feedback.

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### Original Solutions
(no solutions)