12.0-preview1

Issues

• A cancelled connection open does not reach interceptors: the async path calls the sync ConnectionCanceled, and the composite interceptor forwards neither

  area-interception
  Bug

  dotnet/efcore#39254 · Filter by author PatrizioRicciardelloAtSqlService opened on Oct 14, 2026 · 12.0-preview1
  

• JsonColumn with primitive collection in Select throws NullReference exception

  area-primitive-collectionsarea-querycustomer-reported
  Bug

  dotnet/efcore#39255 · Filter by author Xriuk opened on Oct 14, 2026 · 12.0-preview1
  

• EF Tasks package docs and startup validation still recommend removed EFStartupProject property

  area-tools
  Task

  dotnet/efcore#39275 · Filter by author nickna opened on Oct 16, 2026 · 12.0-preview1
  

• Query precompiler throws Non-IQueryable first parameter for ThenInclude

  area-precompiled-queriesarea-query
  Bug

  dotnet/efcore#39274 · Filter by author nickna opened on Oct 16, 2026 · 12.0-preview1
  1

  

• Query precompiler rejects class constant as unknown identifier in predicate

  area-precompiled-queries
  Bug

  dotnet/efcore#39273 · Filter by author nickna opened on Oct 16, 2026 · 12.0-preview1
  1

  

• Query precompiler throws parameter-evaluation NRE for captured object properties

  area-precompiled-queriesarea-query
  Bug

  dotnet/efcore#39272 · Filter by author nickna opened on Oct 16, 2026 · 12.0-preview1
  1

  

• Query precompilation throws EvaluateOperand NullReferenceException for scalar ExecuteUpdate value setter

  area-bulkupdatearea-precompiled-queriesarea-query
  Bug

  dotnet/efcore#39271 · Filter by author nickna opened on Oct 16, 2026 · 12.0-preview1
  1

  

• Query precompiler rejects required-member DTO initializer because its constructor translates to an invocation

  area-precompiled-queries
  Bug

  dotnet/efcore#39302 · Filter by author nickna opened on Oct 16, 2026 · 12.0-preview1
  1

  

• Query precompiler rejects an integer zero implicitly converted to decimal in a projection

  area-precompiled-queries
  Bug

  dotnet/efcore#39303 · Filter by author nickna opened on Oct 16, 2026 · 12.0-preview1
  1

  

• Query precompiler fails to lift a double branch in a target-typed nullable conditional

  area-precompiled-queries
  Bug

  dotnet/efcore#39304 · Filter by author nickna opened on Oct 16, 2026 · 12.0-preview1
  1

  

• Precompiled queries reconstruct nullable-long coalesce with nullable result in anonymous projection

  area-precompiled-queriesarea-query
  Bug

  dotnet/efcore#39309 · Filter by author nickna opened on Oct 17, 2026 · 12.0-preview1
  1

  

• Precompiled queries evaluate guarded Nullable<T>.Value during design-time parameter extraction

  area-precompiled-queriesarea-query
  Bug

  dotnet/efcore#39308 · Filter by author nickna opened on Oct 17, 2026 · 12.0-preview1
  1

• Query never returns (infinite loop on the client) when grouping by a value-converted reference type and projecting the group's elements

  area-querycustomer-reported
  Bug

  dotnet/efcore#39366 · Filter by author benedict-odonovan opened on Oct 22, 2026 · 12.0-preview1

• Add a bulk configuration API for JsonValueReaderWriter

  area-jsonarea-model-building
  Feature

  dotnet/efcore#31316 · Filter by author roji opened on Jul 19, 2023 · 12.0-preview1
  1

  

• Create fluent API for JsonValueReaderWriter on a property

  area-jsonarea-model-building
  Feature

  dotnet/efcore#31647 · Filter by author ajcvickers opened on Sep 6, 2023 · 12.0-preview1
  3