.NET 10 NU1015: Fix PackageReference Without Version Restore Failures

.NET 10 NU1015 turns a PackageReference without a version into a restore error. I like the stricter default because an unbounded direct dependency can quietly resolve the lowest package version. The catch is that versionless XML is also the correct shape for NuGet Central Package Management (CPM). A mechanical “add Version everywhere” repair can undo the policy your repository intended to enforce. I use a simple split: first decide who owns the version, then make restore prove the answer. Why .NET 10 NU1015 stops the build Before .NET 10, NuGet reported NU1604 when a direct reference had no inclusive lower bound. Restore could continue and select the lowest version available from the configured sources. Starting with .NET 10, the same mistake produces NU1015 and restore fails. Microsoft documents this as a stable behavioral change in the .NET 10 compatibility guidance . Here is the ambiguous project entry: <ItemGroup> <PackageReference Include= "Demo.Greeting" /> </ItemGroup> If this is a normal direct reference, the project is missing its version. If CPM is active, the project is correct and the version should live elsewhere. The NU1015 diagnostic reference calls out a common failure mode: a project that expected CPM was copied into a location where CPM is disabled or its props file is no longer discovered. That distinction matters more than silencing the error. It tells me whether the project file or the repository-level package policy is broken. The timing can be misleading. An SDK upgrade may expose an old direct reference that had always relied on lowest-version resolution, while a repository move may break a previously valid CPM import. I inspect the failing project's evaluated inputs, nearby props files, and recent path changes before editing package metadata. That keeps a restore migration from turning into an accidental package-management migration. Fix the owner, not only the XML For a direct reference, I add an explicit version: <PackageReference Include=