For an unknown reason some of our builds started to fail suddenly. A look at the build log, showed us the following error message:
##[error]Error: unable to get local issuer certificate
An error message we had seen before…
The error occurred only on one of our build agents when trying to download a newer nuget version as currently available.
We couldn’t find a good solution but as a workaround we manually downloaded the latest nuget version and copied it to the tools folder at:
<agent directory>\_work\_tool\NuGet