Errors when trying to build a NET CORE project on Linux?

Question

linux

There are two virtual machines: Win 7 and Ubuntu 19.10
Both have Net Core 3.0 installed
On Windows, projects are assembled, everything worked under Linux until reboot, then when trying to build, timeout errors fall:

/usr/share/dotnet/sdk/3.0.101/NuGet.targets(123,5): error : Unable to load the service index for source https://api.nuget.org/v3/index.json. [/home/anton/Documents/myTest/myTest.csproj]
/usr/share/dotnet/sdk/3.0.101/NuGet.targets(123,5): error :   The download of 'https://api.nuget.org/v3/index.json' timed out because no data was received for 60000ms. [/home/anton/Documents/myTest/myTest.csproj]
/usr/share/dotnet/sdk/3.0.101/NuGet.targets(123,5): error :   Exception of type 'System.TimeoutException' was thrown. [/home/anton/Documents/myTest/myTest.csproj]

How to overcome it? On Ubuntu 18.04, the story is about the same, only the SSL connection does not go through there before new.

Answer 1

Looks like sdk-3.0 is not supported on Ubuntu. The problem was solved by changing the version of the framework.
In the project folder, the .csproj file changed
to
Naturally sdk-2.2 should be installed. I hope version 3.1 will fix this problem.