Application Diagnostics

Startup Error

The normal application could not complete startup. This fallback page is intentionally shown so setup issues are visible on new devices.

Database setup recommendation

The startup error looks related to database connection, migration, or schema setup.

  1. Check DynamicConnectionStrings:DefaultConnection in appsettings.json and confirm server, port, database, user, password, and SslMode are correct.
  2. Apply pending migrations: dotnet ef database update --project CompanyDxPortal.Infrastructure --startup-project CompanyDxPortal.Web
  3. If the app is locking build files, stop the running app, then run: dotnet build CompanyDxPortal.Web\CompanyDxPortal.Web.csproj
  4. If a column is missing, confirm the migration exists and appears in: dotnet ef migrations list --project CompanyDxPortal.Infrastructure --startup-project CompanyDxPortal.Web
  5. For local/dev MySQL SSL issues, add SslMode=None to the connection string only when your environment allows it.
  6. If startup seeding is needed, temporarily set Database:RunStartupTasks to true, start once, then set it back to false if desired.
EnvironmentProduction
Content Root/var/www/apps/tpc-dx
Timestamp2026-07-29 14:31:40 +00:00
System.InvalidOperationException: An exception has been raised that is likely due to a transient failure. Consider enabling transient error resiliency by adding 'EnableRetryOnFailure()' to the 'UseMySql' call.
 ---> MySqlConnector.MySqlException (0x80004005): Unable to connect to any of the specified MySQL hosts.
   at MySqlConnector.Core.ServerSession.OpenTcpSocketAsync(ConnectionSettings cs, ILoadBalancer loadBalancer, Activity activity, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/Core/ServerSession.cs:line 1283
   at MySqlConnector.Core.ServerSession.ConnectAsync(ConnectionSettings cs, MySqlConnection connection, Int64 startingTimestamp, ILoadBalancer loadBalancer, Activity activity, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/Core/ServerSession.cs:line 427
   at MySqlConnector.Core.ServerSession.ConnectAndRedirectAsync(ILogger connectionLogger, ILogger poolLogger, IConnectionPoolMetadata pool, ConnectionSettings cs, ILoadBalancer loadBalancer, MySqlConnection connection, Action`4 logMessage, Int64 startingTimestamp, Activity activity, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/Core/ServerSession.cs:line 697
   at MySqlConnector.Core.ServerSession.ConnectAndRedirectAsync(ILogger connectionLogger, ILogger poolLogger, IConnectionPoolMetadata pool, ConnectionSettings cs, ILoadBalancer loadBalancer, MySqlConnection connection, Action`4 logMessage, Int64 startingTimestamp, Activity activity, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/Core/ServerSession.cs:line 702
   at MySqlConnector.MySqlConnection.CreateSessionAsync(ConnectionPool pool, Int64 startingTimestamp, Activity activity, Nullable`1 ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/MySqlConnection.cs:line 1099
   at MySqlConnector.MySqlConnection.OpenAsync(Nullable`1 ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/MySqlConnection.cs:line 567
   at MySqlConnector.MySqlConnection.Open() in /_/src/MySqlConnector/MySqlConnection.cs:line 522
   at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenDbConnection(Boolean errorsExpected)
   at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenInternal(Boolean errorsExpected)
   at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.Open(Boolean errorsExpected)
   at Pomelo.EntityFrameworkCore.MySql.Storage.Internal.MySqlRelationalConnection.Open(Boolean errorsExpected)
   at Pomelo.EntityFrameworkCore.MySql.Storage.Internal.MySqlDatabaseCreator.<>c__DisplayClass18_0.<Exists>b__0(DateTime giveUp)
   at Microsoft.EntityFrameworkCore.ExecutionStrategyExtensions.<>c__DisplayClass12_0`2.<Execute>b__0(DbContext _, TState s)
   at Pomelo.EntityFrameworkCore.MySql.Storage.Internal.MySqlExecutionStrategy.Execute[TState,TResult](TState state, Func`3 operation, Func`3 verifySucceeded)
   --- End of inner exception stack trace ---
   at Pomelo.EntityFrameworkCore.MySql.Storage.Internal.MySqlExecutionStrategy.Execute[TState,TResult](TState state, Func`3 operation, Func`3 verifySucceeded)
   at Microsoft.EntityFrameworkCore.ExecutionStrategyExtensions.Execute[TState,TResult](IExecutionStrategy strategy, TState state, Func`2 operation, Func`2 verifySucceeded)
   at Microsoft.EntityFrameworkCore.ExecutionStrategyExtensions.Execute[TState,TResult](IExecutionStrategy strategy, TState state, Func`2 operation)
   at Pomelo.EntityFrameworkCore.MySql.Storage.Internal.MySqlDatabaseCreator.Exists(Boolean retryOnNotExists)
   at Pomelo.EntityFrameworkCore.MySql.Storage.Internal.MySqlDatabaseCreator.Exists()
   at Microsoft.EntityFrameworkCore.Migrations.Internal.Migrator.Migrate(String targetMigration)
   at Microsoft.EntityFrameworkCore.RelationalDatabaseFacadeExtensions.Migrate(DatabaseFacade databaseFacade)
   at Program.<Main>$(String[] args) in C:\EPDX Projects\MY VPS APPLICATIONS\CompanyDxPortal\CompanyDxPortal.Web\Program.cs:line 109