Details about Problem

NuGet product used (NuGet.exe | VS UI | Package Manager Console | dotnet.exe): Package Manager Console

NuGet version (x.x.x.xxx): 4.9.2.5706

dotnet.exe --version (if appropriate):

VS version (if appropriate): 15.9.4

OS version (i.e. win10 v1607 (14393.321)):

Worked before? If so, with which NuGet version:

Detailed repro steps so we can see the same problem

Adding a constraint to a packages.config file to limit the allowed versions does not seem to have any affect on Get-Package -Updates.

1. Create a class library project.
2. Install Newtonsoft.Json 9.0.1 - using a packages.config file.
3. Add a constraint to the packages.config file to ensure latest is not used: allowedVersions="[9.0,11)".
4. Run Get-Package -Updates

Expected result:

Version 10.0.3 is shown in the output.

Actual result:

12.0.1 is shown in the Package Console output.
The Manage Packages information shows the correct update of 10.0.3 being available.
...

Other suggested things

Verbose Logs

Please include verbose logs (NuGet.exe -verbosity detailed | dotnet.exe --verbosity diag | etc...)

Sample Project

Very helpful if you can zip a project and paste into this issue!