I'm getting an error compiling this component.

Error as below:

".NET Compilation.

Project file contains ToolsVersion="12.0". This toolset may be unknown or missing, in which case you may be able to resolve this by installing the appropriate version of MSBuild, or the build may have been forced to a particular ToolsVersion for policy reasons. Treating the project as if it had ToolsVersion="4.0". For more information, please see http://go.microsoft.com/fwlink/?LinkId=291333.
C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Common.targets(983,5): warning MSB3644: The reference assemblies for framework ".NETFramework,Version=v4.6.1" were not found. To resolve this, install the SDK or Targeting Pack for this framework version or retarget your application to a version of the framework for which you have the SDK or Targeting Pack installed. Note that assemblies will be resolved from the Global Assembly Cache (GAC) and will be used in place of reference assemblies. Therefore your assembly may not be correctly targeted for the framework you intend.
C:\Users\62955\AppData\Local\Temp\1\d31c8f33-a831-4f61-abbc-4c7c3641edbb\Source\NET\ConverterAPI_Client.csproj(149,5): error : Este projeto faz referˆncia a pacotes do NuGet que n?o est?o presentes neste computador. Use a Restaura‡?o de Pacotes do NuGet para baix?-los.  Para obter mais informa‡?es, consulte http://go.microsoft.com/fwlink/?LinkID=322105. O arquivo ausente ‚ packages\Microsoft.Bcl.Build.1.0.21\build\Microsoft.Bcl.Build.targets."