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Tag: errors

127 posts · Page 7 of 13

2026-07-17 errors csharp dotnet

Fix: System.InvalidOperationException: Headers are read-only, response has already started

You set a header, status code, or content type after the body was already flushed. Set all headers before the first write, or guard with HttpResponse.HasStarted and OnStarting.

2026-07-17 errors csharp dotnet

Fix: "The property could not be mapped, because it is not a supported primitive type or a valid entity type" in EF Core 11

EF Core hit a property it does not know how to store. Map it as a complex type, convert it with HasConversion, give it a key, or ignore it with [NotMapped].

2026-07-06 errors dotnet dotnet-11

Fix: "415 Unsupported Media Type" from a minimal API endpoint in ASP.NET Core 11

A minimal API returns 415 when the request Content-Type does not match what the endpoint binds. Send Content-Type: application/json for a body-bound type, or use [FromForm] for form and file uploads.

2026-07-06 errors csharp csharp-14

Fix: CS9035 "Required member 'X' must be set in the object initializer" in C#

CS9035 means a member marked required was not assigned. Set it in the object initializer, or add a constructor annotated with [SetsRequiredMembers] that assigns every required member.

2026-07-06 errors flutter dart

Fix: Riverpod 3.0 throws ProviderException instead of the original error

Riverpod 3.0 wraps errors thrown while reading a provider in a ProviderException. Catch that type and read e.exception to get your original error back, or use AsyncValue.error which is unwrapped.

2026-07-05 errors flutter dart

Fix: Cannot provide both a color and a decoration in a Flutter Container

Move the color inside the decoration: use decoration: BoxDecoration(color: ...) instead of passing both color and decoration to the same Container.

2026-07-05 errors flutter dart

Fix: Incorrect use of ParentDataWidget. Expanded widgets must be placed inside Flex widgets (Flutter)

This error means an Expanded or Flexible is not a direct child of a Row, Column, or Flex. Move it directly under the flex widget, or drop Expanded if the parent is not a flex.

2026-07-05 errors flutter dart

Fix: A RenderViewport expected a child of type RenderSliver but received a child of type RenderBox (Flutter CustomScrollView)

The slivers list of a CustomScrollView only accepts slivers. Wrap box widgets in SliverToBoxAdapter, or swap ListView/Padding/Column for SliverList and SliverPadding.

2026-07-04 errors efcore dotnet

Fix: "The LINQ expression could not be translated" in EF Core 11

EF Core 11 throws this when a Where or OrderBy calls a method it cannot turn into SQL. Rewrite the predicate into translatable operators, or pull the data client-side with AsEnumerable first.

2026-07-04 errors efcore dotnet

Fix: "The required column 'X' was not present in the results of a 'FromSql' operation" in EF Core 11

EF Core throws this when your raw SQL does not return every column the entity maps to, or the column names do not match. Return all mapped columns with matching names, or query a scalar/keyless type instead.