Sqlpackage import fails with error 'Json serialization is not supported on .NET Core'

[abydal]

I get an error importing a database from a customer. This is a procedure I have done dozens of times, so don't really understand whats different now.
From what I can see it complains about the files in /Data being json-formatted, but is this reallly a new thing?

• SqlPackage or DacFx Version: 162.4.92.3
• .NET Framework (Windows-only) or .NET Core: NET8
• Environment (local platform and source/target platforms): Windows - trying to import to both Azure Sql and local docker instance with Sql Server

I don't really know how the backpac file was produced but I get this exception when I try to import it:

Data plan execution failed with message One or more errors occurred. (One or more errors occurred. (One or more errors occurred. (Json serialization is not supported on .NET Core)))
 Exception: Microsoft.SqlServer.Dac.Data.DataException: Data plan execution failed with message One or more errors occurred. (One or more errors occurred. (One or more errors occurred. (Json serialization is not supported on .NET Core)))
 ---> System.AggregateException: One or more errors occurred. (One or more errors occurred. (One or more errors occurred. (Json serialization is not supported on .NET Core)))
 ---> System.AggregateException: One or more errors occurred. (One or more errors occurred. (Json serialization is not supported on .NET Core))
 ---> System.AggregateException: One or more errors occurred. (Json serialization is not supported on .NET Core)
 ---> System.PlatformNotSupportedException: Json serialization is not supported on .NET Core
   at Microsoft.Data.Tools.Schema.Sql.Dac.Data.Import.ImportTablePartHelper.ImportTableParts() in C:\__w\1\s\Source\SchemaSql\Dac\Data\Import\ImportTablePartHelper.cs:line 68
   at Microsoft.Data.Tools.Schema.Sql.Dac.Data.Import.ImportTableHelper.ImportTableParts(ImportTableMetadata tableMetadata, IEnumerable`1 partUris) in C:\__w\1\s\Source\SchemaSql\Dac\Data\Import\ImportTableHelper.cs:line 326
   at Microsoft.Data.Tools.Schema.Sql.Dac.Data.Import.ImportTableHelper.<>c__DisplayClass57_0.<StartImportTableParts>b__0() in C:\__w\1\s\Source\SchemaSql\Dac\Data\Import\ImportTableHelper.cs:line 315
   at Microsoft.Data.Tools.Schema.Sql.Dac.Logging.DacLogContext.<>c__DisplayClass22_0.<AddContext>b__0() in C:\__w\1\s\Source\SchemaSql\Dac\Logging\DacLogContext.cs:line 203
   at Microsoft.Data.Tools.Schema.Sql.Dac.Data.Import.ImportBacpacHelper.PackageReaderTaskFactory.<>c__DisplayClass5_0.<GetExecutableAction>b__0() in C:\__w\1\s\Source\SchemaSql\Dac\Data\Import\ImportBacpacHelper.cs:line 539
   at Microsoft.Data.Tools.Schema.Sql.Dac.Logging.DacLogContext.<>c__DisplayClass22_0.<AddContext>b__0() in C:\__w\1\s\Source\SchemaSql\Dac\Logging\DacLogContext.cs:line 203
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location ---
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)
   --- End of inner exception stack trace ---
   --- End of inner exception stack trace ---
   --- End of inner exception stack trace ---
   at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
   at System.Threading.Tasks.Task.Wait(Int32 millisecondsTimeout, CancellationToken cancellationToken)
   at System.Threading.Tasks.Task.Wait()
   at Microsoft.Data.Tools.Schema.Sql.Dac.Data.Import.ImportBacpacHelper.ImportBacpac() in C:\__w\1\s\Source\SchemaSql\Dac\Data\Import\ImportBacpacHelper.cs:line 284
   at Microsoft.Data.Tools.Schema.Sql.Dac.Data.ImportTablesStep.Execute() in C:\__w\1\s\Source\SchemaSql\Dac\Data\ImportTablesStep.cs:line 67
   at Microsoft.Data.Tools.Schema.Sql.Deployment.Steps.DacBulkCopyStep.Execute(IDbConnection conn, CancellationToken token, LoggingContext loggingContext) in C:\__w\1\s\Source\SchemaSql\Deployment\Steps\DacBulkCopyStep.cs:line 92
   at Microsoft.Data.Tools.Schema.Sql.Deployment.SqlPlanDeployment.Execute(DeploymentPlanHandle plan, SqlConnectionFactory connectionFactory, String targetDatabaseName, Boolean IsAzureTarget, String databaseScriptPath, String masterScriptPath, CancellationToken cancelToken, LoggingContext loggingContext)
   at Microsoft.SqlServer.Dac.Deployment.PlanExecutor.Execute(DeploymentPlan plan, SqlConnectionFactory connectionFactory, Boolean isAzureTarget, LoggingContext loggingContext, CancellationToken cancelToken) in C:\__w\1\s\Source\DeploymentApi\Deployment\PlanExecutor.cs:line 93

Any help will be appreciated here 🙏