As of version 8.19, the New Relic .NET Agent Windows msi installer also installs .NET Core support for IIS apps. Previously this required a separate manual install. In most cases the installer will automatically place the updated .NET Core files in the New Relic directory and update the environment variables to point to the correct new location. For new installs you should use the msi to install support for both .NET Core and .NET Framework apps.
The installer now sets both .NET Framework and .NET Core apps to use the same
C:\ProgramData\New Relic\.NET Agent\newrelic.config and the same
C:\ProgramData\New Relic\.NET Agent\extensions\ directory for custom instrumentation.
One issue can occur if you had set the required CORECLR_ environment variables in your web.config as in the following example:
The AspNetCoreModule does not override environment variables variables set this way but instead appends the value. This means that
CORECLR_PROFILING_ENABLED=1;1 which can be seen via Process Explorer. This “duplicated” environment variable is invalid and will cause the agent to no longer report data:
After upgrading to 8.19 or higher we recommend removing the CORECLR_ settings from your web.config to resolve this issue. This does not affect the NEW_RELIC_APP_NAME which can still be used as this level.