I've got to Task 3 (Convert your v14 C/AL application to AL) of the procedure on this link:-
which has a link to another page below:-
On this page, I've got to Task 7: Create and build an AL project for custom base application.
On attempting step 11: Build and compile your project (press Ctrl+Shift+B), it fails with the errors below:-
error AL0999: Internal error: System.AggregateException: One or more errors occurred. (Object reference not set to an instance of an object.)
---> System.NullReferenceException: Object reference not set to an instance of an object.
at Microsoft.Dynamics.Nav.CodeAnalysis.DotNet.Cecil.CecilExtensions.ImportTypeDefinition(ModuleDefinition module, Type t) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\DotNet\Cecil\CecilExtensions.cs:line 39
at Microsoft.Dynamics.Nav.CodeAnalysis.DotNet.Cecil.CecilDotNetTypeInfoProvider..ctor(ReaderParameters moduleReaderParameters) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\DotNet\Cecil\CecilDotNetTypeInfoProvider.cs:line 128
at Microsoft.Dynamics.Nav.CodeAnalysis.DotNet.Cecil.CecilDotNetTypeInfoProvider.Create(ReaderParameters moduleReaderParameters) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\DotNet\Cecil\CecilDotNetTypeInfoProvider.cs:line 118
at Microsoft.Dynamics.Nav.CodeAnalysis.DotNet.Cecil.CecilDotNetTypeLoader.CreateTypeInfoProvider() in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\DotNet\Cecil\CecilDotNetTypeLoader.cs:line 139
at Microsoft.Dynamics.Nav.CodeAnalysis.DotNet.Cecil.CecilDotNetTypeLoader.get_TypeInfoProvider() in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\DotNet\Cecil\CecilDotNetTypeLoader.cs:line 48
at Microsoft.Dynamics.Nav.CodeAnalysis.DotNet.Cecil.CecilDotNetTypeLoader.<LoadAssembly>b__13_0(String assemblyName) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\DotNet\Cecil\CecilDotNetTypeLoader.cs:line 68
at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory)
at Microsoft.Dynamics.Nav.CodeAnalysis.DotNet.Cecil.CecilDotNetTypeLoader.LoadAssembly(String fullAssemblyName) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\DotNet\Cecil\CecilDotNetTypeLoader.cs:line 64
at Microsoft.Dynamics.Nav.CodeAnalysis.DotNet.DotNetResolver.LoadAssembly(String fullAssemblyName) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\DotNet\DotNetResolver.cs:line 31
at Microsoft.Dynamics.Nav.CodeAnalysis.Symbols.SourceDotNetAssemblySymbol.<LazyGetAssembly>b__33_0(DiagnosticBag diagnostics) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Symbols\Source\SourceDotNetAssemblySymbol.cs:line 226
at Microsoft.Dynamics.Nav.CodeAnalysis.Symbols.Symbol.LazySetSymbol(Action`1 setSymbol, CompletionPart completionValue, SymbolCompletionState& state) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Symbols\Symbol.cs:line 572
at Microsoft.Dynamics.Nav.CodeAnalysis.Symbols.SourceDotNetAssemblySymbol.LazyGetAssembly() in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Symbols\Source\SourceDotNetAssemblySymbol.cs:line 214
at Microsoft.Dynamics.Nav.CodeAnalysis.Symbols.SourceDotNetAssemblySymbol.get_AssemblyInfo() in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Symbols\Source\SourceDotNetAssemblySymbol.cs:line 52
at Microsoft.Dynamics.Nav.CodeAnalysis.Symbols.SourceDotNetTypeDeclarationSymbol.<LazyGetType>b__26_0(DiagnosticBag diagnostics) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Symbols\Source\SourceDotNetTypeDeclarationSymbol.cs:line 125
at Microsoft.Dynamics.Nav.CodeAnalysis.Symbols.Symbol.LazySetSymbol(Action`1 setSymbol, CompletionPart completionValue, SymbolCompletionState& state) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Symbols\Symbol.cs:line 572
at Microsoft.Dynamics.Nav.CodeAnalysis.Symbols.SourceDotNetTypeDeclarationSymbol.LazyGetType() in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Symbols\Source\SourceDotNetTypeDeclarationSymbol.cs:line 123
at Microsoft.Dynamics.Nav.CodeAnalysis.Symbols.SourceDotNetTypeDeclarationSymbol.get_DotNetType() in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Symbols\Source\SourceDotNetTypeDeclarationSymbol.cs:line 55
at Microsoft.Dynamics.Nav.CodeAnalysis.Symbols.ModuleSymbol.GetObjectSymbolByName(ImmutableDictionary`2 objectsByName, SymbolKind kind, String name) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Symbols\ModuleSymbol.cs:line 386
at Microsoft.Dynamics.Nav.CodeAnalysis.Symbols.SourceModuleSymbol.GetObjectSymbolByName(SymbolKind kind, String name) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Symbols\Source\SourceModuleSymbol.cs:line 1353
at Microsoft.Dynamics.Nav.CodeAnalysis.ReferenceManager.ResolveDotNetObjectSymbolsByName(ModuleSymbol referencingModule, String name) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\SymbolReference\ReferenceManager.cs:line 364
at Microsoft.Dynamics.Nav.CodeAnalysis.ReferenceManager.GetObjectSymbolsByNameAcrossModules(ModuleSymbol referencingModule, SymbolKind kind, String name) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\SymbolReference\ReferenceManager.cs:line 330
at Microsoft.Dynamics.Nav.CodeAnalysis.Binder.GetApplicationObjectTypeSymbols(ObjectNameOrIdSyntax objectNameOrId, SymbolKind kind) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Binder\Binder_Symbols.cs:line 321
at Microsoft.Dynamics.Nav.CodeAnalysis.Binder.GetSubtypedDataType(SubtypedDataTypeSyntax syntax, SymbolKind kind, DiagnosticBag diagnostics) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Binder\Binder_Symbols.cs:line 303
at Microsoft.Dynamics.Nav.CodeAnalysis.Binder.BindSubTypedDataType(Symbol ownerSymbol, SubtypedDataTypeSyntax syntax, DiagnosticBag diagnostics) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Binder\Binder_Symbols.cs:line 289
at Microsoft.Dynamics.Nav.CodeAnalysis.Binder.BindType(Symbol ownerSymbol, DataTypeSyntax syntax, DiagnosticBag diagnostics) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Binder\Binder_Symbols.cs:line 108
at Microsoft.Dynamics.Nav.CodeAnalysis.Binder.BindVariableOrParameterType(Symbol ownerSymbol, TypeReferenceBaseSyntax syntax, DiagnosticBag diagnostics) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Binder\Binder_Symbols.cs:line 490
at Microsoft.Dynamics.Nav.CodeAnalysis.Binder.BindVariableType(Symbol ownerSymbol, TypeReferenceBaseSyntax syntax, DiagnosticBag diagnostics) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Binder\Binder_Symbols.cs:line 420
at Microsoft.Dynamics.Nav.CodeAnalysis.Symbols.SourceVariableSymbol.LazyGetType() in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Symbols\Source\SourceVariableSymbol.cs:line 107
at Microsoft.Dynamics.Nav.CodeAnalysis.Symbols.SourceVariableSymbol.get_Type() in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Symbols\Source\SourceVariableSymbol.cs:line 60
at Microsoft.Dynamics.Nav.CodeAnalysis.Symbols.SourceAttributeSymbol.CheckAttribute() in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Symbols\Source\SourceAttributeSymbol.cs:line 312
at Microsoft.Dynamics.Nav.CodeAnalysis.Symbols.SourceAttributeSymbol.ForceComplete(SourceLocation locationOpt, CancellationToken cancellationToken) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Symbols\Source\SourceAttributeSymbol.cs:line 277
at Microsoft.Dynamics.Nav.CodeAnalysis.Symbols.SourceVariableSymbol.ForceCompleteAttributes(SourceLocation locationOpt, CancellationToken cancellationToken) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Symbols\Source\SourceVariableSymbol.cs:line 184
at Microsoft.Dynamics.Nav.CodeAnalysis.Symbols.SourceVariableSymbol.ForceComplete(SourceLocation locationOpt, CancellationToken cancellationToken) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Symbols\Source\SourceVariableSymbol.cs:line 122
at Microsoft.Dynamics.Nav.CodeAnalysis.Symbols.ObjectMembers`1.ForceMembersCompleteAndCheckUniqueness(SourceLocation locationOpt, DiagnosticBag diagnostics, CancellationToken cancellationToken, Predicate`1 excludeFromNameUniqueness) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Symbols\Members\ObjectMembers.cs:line 175
at Microsoft.Dynamics.Nav.CodeAnalysis.Symbols.ObjectMembers`1.ForceCompleteMembers(SourceLocation locationOpt, CancellationToken cancellationToken, Predicate`1 excludeFromNameUniqueness) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Symbols\Members\ObjectMembers.cs:line 1040
at Microsoft.Dynamics.Nav.CodeAnalysis.Symbols.ObjectMembers`1.ForceComplete(SourceLocation locationOpt, CancellationToken cancellationToken, Predicate`1 excludeFromNameUniqueness) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Symbols\Members\ObjectMembers.cs:line 990
at Microsoft.Dynamics.Nav.CodeAnalysis.Symbols.SourcePageTypeSymbol.ForceComplete(SourceLocation locationOpt, CancellationToken cancellationToken) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Symbols\Source\SourcePageTypeSymbol.cs:line 50
at Microsoft.Dynamics.Nav.CodeAnalysis.Symbols.SourceModuleSymbol.ForceCompleteMemberByLocation(SourceLocation locationOpt, Symbol member, CancellationToken cancellationToken) in D:\a\1\s\source\Prod\Microsoft.Dynamics.Nav.CodeAnalysis\Symbols\Source\SourceModuleSymbol.cs:line 223
at System.Threading.Tasks.Parallel.<>c__DisplayClass19_0`1.<ForWorker>b__1(RangeWorker& currentWorker, Int32 timeout, Boolean& replicationDelegateYieldedBeforeCompletion)
Any ideas what's causing this to fail?