We have a .NET 6 application which makes requests to a third party API. About a month ago, requests from most of our computers started failing. The error we get is:

System.Net.Http.HttpRequestException: An error occurred while sending the request. ---> 
System.IO.IOException: The response ended prematurely.

The error only happens when application is launched with a normal user. It works when launched as administrator.

What I figured out

Application tries to access registry keys that are related to certificates and fails.

Data from process explorer:

Unique paths that it tries to access:

I also noticed that this issue goes away when SQL server is updated to version 2022, because some certificates get removed/added/modified.

I’d like to know what could have caused this. Could this be a group policy rule, perhaps an unrelated one? Certificates expired? Is there a way to figure out what happened, and if not, what would be the best way to go about fixing this issue? For now it seems that updating SQL server is the only viable way.