Failing to change TargetFramework to TargetFrameworks when multi-targeting gives unclear error message

[burtonrodman]

Type: Feature Request

1. in a C# project targeting a single TFM with "TargetFramework",
2. add a second TFM (without changing the TargetFramework element to TargetFrameworks)
3. receive the error message below that is not clear, or even pointing to the proper source file that contains the issue

Determining projects to restore...
C:\Program Files\dotnet\sdk\9.0.101\NuGet.targets(170,5): error : Sequence contains no matching element [D:\source\MySolution.sln]

Extension version: 2.55.29
VS Code version: Code 1.95.3 (f1a4fb101478ce6ec82fe9627c43efbf9e98c813, 2024-11-13T14:50:04.152Z)
OS version: Windows_NT x64 10.0.22631
Modes:

[burtonrodman]

EXPECTED RESULT:
a more clear error message is displayed like:

MyProject.csproj(7,5):  error:  The TargetFramework property may only contain a single TFM.  Did you mean to use TargetFrameworks?

[burtonrodman]

or better yet, either deprecate the TargetFramework (singular) property and push everyone to use TargetFrameworks, or add support for multiple TFMs in the TargetFramework property and deprecate TargetFrameworks (plural)