Unable to find version '' of package 'MSBuild.Microsoft.VisualStudio.Web.targets': NuGet "WARNING: Error: SendFailure (Error writing headers)"

Hi, I’m very new to travis and I’m getting the below error

1.73s$ nuget restore DMX.sln
612WARNING: Error: SendFailure (Error writing headers)
613Unable to find version ‘’ of package
614The command “nuget restore DMX.sln” failed and exited with 1 during .

below is my config:

language: csharp
solution: DMX.sln
#mono: 3.12.0
mono: none
dotnet: 3.1.101

  • sudo apt install nuget
  • nuget restore DMX.sln
  • dotnet build DMX.sln -c Release

Any help greatly appreciated.

Error during restoring packages on Ubuntu · Issue #4089 · dotnet/runtime suggests that this happens when you have outdated or no certificates in the Mono key store.

Try updating the ca-certificates Apt package.

https://www.nuget.org/packages/MSBuild.Microsoft.VisualStudio.Web.targets/ and https://docs.microsoft.com/en-us/dotnet/core/tools/dotnet-restore also suggest using dotnet restore instead of nuget restore.

If that doesn’t help, please link to a build, I can’t say anything else otherwise.