Fixes
Error messages, decoded: the exact text you searched for, what it actually means, the fix, and where it bit us in a real build.
MAUI, Android and Windows apps · 12Blazor · 13Ollama and local AI · 12EF Core, SQL Server and PostgreSQL · 28ASP.NET Core, C# and the .NET SDK · 21Docker, Git and WSL · 19
MAUI, Android and Windows apps 12 posts
- CA1422 in .NET MAUI: 'Window.SetStatusBarColor(Color)' is obsoleted on: 'Android' 35.0 and later
- NETSDK1147: To build this project, the following workloads must be installed: maui-android
- NU1102 on dotnet publish -r win-x64 for a MAUI app: NuGet can't find a Mono runtime pack
- MSB3030: Could not copy the file: a Windows App SDK build that dies past MAX_PATH
- D8: Type androidx.fragment.app.FragmentKt is defined multiple times (MAUI + Firebase)
- Blazor Hybrid on Android: content hidden under the status bar, env(safe-area-inset-top) is 0
- MAUI Android: 'No maps app' or ActivityNotFoundException with Google Maps installed
- Firebase says '1 delivered' but Android shows nothing: adb force-stop puts your app in stopped state
- CS0104: 'View' is an ambiguous reference between Android.Views.View and Microsoft.Maui.Controls.View
- AppNotificationManager.Show() displays no toast on Windows: the unpackaged-app identity problem
- MAUI SecureStorage.GetAsync throws on Android after a keystore reset
- apksigner verify prints a valid signature but your script reports failure: it is the shell, not apksigner
Blazor 13 posts
- Blazor: 'Found markup element with unexpected name' (RZ10012)
- Blazor: 'Cannot provide a value for property' (no registered service)
- Blazor: 'Headers are read-only, response has already started'
- Blazor: 'The POST request does not specify which form is being submitted'
- Blazor: 'Cannot pass the parameter ChildContent to component with rendermode InteractiveServerRenderMode'
- Blazor: 'JavaScript interop calls cannot be issued at this time' during prerendering
- Blazor: 'The current thread is not associated with the Dispatcher. Use InvokeAsync()'
- Blazor: 'Object of type X does not have a property matching the name Y' (a misspelled parameter)
- Blazor: 'the required endpoints are not mapped on the server' for an InteractiveServer component
- Blazor serves empty CSS and JS files: MapStaticAssets without ASPNETCORE_ENVIRONMENT=Development
- Blazor: the h1 shows a focus ring after navigation (FocusOnNavigate and tabindex=-1)
- CS0542: member names cannot be the same as their enclosing type (a Blazor @inject named after its page)
- Blazor: 'An unhandled error has occurred' shows on every page after deleting the template CSS
Ollama and local AI 12 posts
- Ollama: 'Error: pull model manifest: file does not exist'
- Ollama from .NET: 'Response status code does not indicate success: 404 (Not Found)'
- Ollama from .NET: 'No connection could be made because the target machine actively refused it'
- Ollama from .NET: 'ModelDoesNotSupportToolsException: gemma3:12b does not support tools'
- Ollama manual install on Linux: 'gzip: stdin: not in gzip format'
- Ollama manual install: 'tar: This does not look like a tar archive'
- Ollama on Linux and WSL: 'could not connect to ollama server'
- Ollama on Linux: 'bind: address already in use' on 127.0.0.1:11434
- Ollama manual install: 'tar: Archive is compressed. Use --zstd option'
- Ollama on Windows: 'bind: Only one usage of each socket address is normally permitted'
- Ollama install on Linux: 'This version requires zstd for extraction'
- Ollama under systemd: 'panic: $HOME is not defined'
EF Core, SQL Server and PostgreSQL 28 posts
- EF Core: 'No database provider has been configured for this DbContext'
- EF Core: 'There is already an object named ... in the database' (SqlException 2714)
- EF Core: 'Unable to resolve service for type AppDbContext while attempting to activate'
- PostgreSQL: 'FATAL: role "app" does not exist'
- PostgreSQL: 'FATAL: database "appdb" does not exist'
- PostgreSQL 15+: 'ERROR: permission denied for schema public'
- PostgreSQL: 'ERROR: relation "customers" does not exist' (42P01)
- PostgreSQL: 'pg_dump: error: aborting because of server version mismatch'
- SQL Server: 'A network-related or instance-specific error occurred' (error 26)
- SQL Server: 'Cannot open database requested by the login. The login failed.' (error 4060)
- SQL Server LocalDB: 'No process is on the other end of the pipe' with User ID=sa (error 233)
- SQL Server: 'Invalid object name' (error 208)
- SQL Server: 'Cannot insert explicit value for identity column when IDENTITY_INSERT is set to OFF' (error 544)
- postgres:18 in Docker: 'database files are incompatible with server' after upgrading from 16
- Docker postgres: '28P01: password authentication failed for user postgres' after changing POSTGRES_PASSWORD
- EF Core: 'The entity type ... requires a primary key to be defined'
- Npgsql: 'Cannot write DateTime with Kind=Local to PostgreSQL type timestamp with time zone'
- EF Core: 'Unable to create a DbContext of type' from dotnet ef migrations add
- EF Core: 'cannot be tracked because another instance with the same key value is already being tracked'
- EF Core: 'The LINQ expression could not be translated' when Where calls a C# method
- PostgreSQL: '23505: duplicate key value violates unique constraint' after seeding rows
- System.Text.Json: 'A possible object cycle was detected' when returning EF Core entities
- EF Core: 'A second operation was started on this context instance before a previous operation completed'
- Docker postgres: 'Database is uninitialized and superuser password is not specified'
- pgvector: 'function min(vector) does not exist'
- postgres:18 Docker container exits immediately: mount the volume at /var/lib/postgresql
- EF Core: two HasIndex calls on the same column create only one index (name them)
- EF Core: 'The model for context has pending changes' in tests while the app migrates fine
ASP.NET Core, C# and the .NET SDK 21 posts
- ASP.NET Core BackgroundService: 'Cannot consume scoped service from singleton IHostedService'
- NuGet: 'error NU1301: Unable to load the service index for source'
- .NET SDK: 'MSB1003: Specify a project or solution file'
- .NET SDK: 'MSB1011: Specify which project or solution file to use'
- dotnet ef: 'No project was found. Change the current working directory or use the --project option'
- .NET: 'You must install or update .NET to run this application' (version 8.0.0)
- ASP.NET Core: 'Unable to configure HTTPS endpoint. No server certificate was specified'
- ASP.NET Core: 'Hosting environment: Production' and port 5000 after dotnet run --no-launch-profile
- dotnet: 'A compatible .NET SDK was not found' when global.json pins a missing SDK
- NETSDK1004: 'Assets file project.assets.json not found' from dotnet build --no-restore
- NETSDK1045: 'The current .NET SDK does not support targeting .NET 10.0' with a global.json pin
- ASP.NET Core: 'Failed to bind to address ...: address already in use' (Kestrel)
- ASP.NET Core: 'Unable to resolve service for type ... while attempting to activate ...'
- ASP.NET Core: 'Cannot consume scoped service ... from singleton ...'
- C# CS8618: 'Non-nullable property must contain a non-null value when exiting constructor'
- SignalR WithAutomaticReconnect() stops reconnecting after four attempts
- dotnet build fails because the DLL is locked: your app (or test host) is still running
- ASP.NET Core: 'Unable to resolve service for type IOutputCacheStore', and why .CacheOutput() alone caches nothing
- CS0104: 'BarcodeReader<T>' is ambiguous between ZXing.Net and ZXing.Net.Bindings.ImageSharp
- dotnet run -nologo: the switch lands in your application's args
- ASP.NET Identity 'Invalid login attempt' with the right password: RequireConfirmedAccount and seeded users
Docker, Git and WSL 19 posts
- Docker: 'invalid reference format: repository name must be lowercase'
- Docker: 'Conflict. The container name is already in use by container'
- Docker: 'pull access denied, repository does not exist or may require docker login'
- Docker: 'failed to resolve reference docker.io/library/postgres:99: not found'
- Docker Compose: 'no configuration file provided: not found'
- Docker in Git Bash: 'cannot access C:/Program Files/Git/data'
- Git: 'fatal: not a git repository (or any of the parent directories)'
- Git: 'Your local changes to the following files would be overwritten by checkout'
- Git: 'warning: in the working copy, LF will be replaced by CRLF'
- Git for Windows: 'fatal: unable to stat ...: Filename too long'
- Docker: 'driver failed programming external connectivity ... port is already allocated'
- Docker on Windows: 'ports are not available ... forbidden by its access permissions'
- Git push: 'fatal: The current branch ... has no upstream branch'
- Git push: '! [rejected] main -> main (fetch first)' and 'failed to push some refs'
- Git pull: 'fatal: refusing to merge unrelated histories'
- WSL sudo: 'Sorry, try again' when you have forgotten the password
- Docker: 'cannot attach stdin to a TTY-enabled container because stdin is not a terminal'
- Git in WSL: 'fatal: detected dubious ownership in repository at /mnt/c/...'
- WSL: 'sudo: a password is required' when a script runs from Windows