WebException: Error: NameResolutionFailure only on Android mono builds

Hi,

I have a managed unity plugin where I send out a simple GET webrequest via Https using the .Net webclient class. This works fine in the Editor or on IOS (IL2CPP) and I am getting a valid response.
However on an Android mono build I receive followin error:

D/dalvikvm( 4106): GC_CONCURRENT freed 524K, 23% free 9880K/12720K, paused 12ms+2ms, total 78ms
W/mono (23070): _wapi_gethostbyname: Need to translate 0 into winsock error
I/Unity (23070): WebException: Error: NameResolutionFailure
I/Unity (23070): at System.Net.HttpWebRequest.EndGetResponse (IAsyncResult asyncResult) [0x00000] in <filename unknown>:0
I/Unity (23070): at System.Net.HttpWebRequest.GetResponse () [0x00000] in <filename unknown>:0
I/Unity (23070): at System.Net.WebClient.GetWebResponse (System.Net.WebRequest request) [0x00000] in <filename unknown>:0
I/Unity (23070): at System.Net.WebClient.DownloadDataCore (System.Uri address, System.Object userToken) [0x00000] in <filename unknown>:0

Anyone any ideas?

 

Oh and I did forget to mention that this error does not occur when I enable the "script debuggin" checkbox for a build

 

Well it works when setting the "Internet Access" checkbox to "required" in the Player settings...

 

thanks so much. It works Perfectly

 

that worked ,Thanks!

 

Thanks for the tip!
Under 2021 it changed a bit there is now a selector with Auto and Require in the player settings.

I think the reason for this is that on Auto Unity only adds the parts of the mono implementation of System.Net when it thinks it is needed (Managed Stripping). I have some usage dependency inception which is of course not recognized by Managed Stripping.

Weirdly using a link.xml file did not help me.

 

For me, ticking Require on the Internet Access setting hasn't fixed the issue.
I've tried solving the ip address myself and and using that as the domain but that didn't help either