Hi,

I'm trying to upgrade from 6.2.0 to 7.3.1 and have an error in the back end when i click on any of the Document Types:

Server Error in '/' Application.

InvalidCompositionException - ContentType with alias 'Page' was added as a Compsition to ContentType with alias 'NonNavigatableSection', but there was a conflict on the PropertyType alias 'umbracoRedirect'. PropertyTypes must have a unique alias across all Compositions in order to compose a valid ContentType Composition.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: Umbraco.Core.Exceptions.InvalidCompositionException: InvalidCompositionException - ContentType with alias 'Page' was added as a Compsition to ContentType with alias 'NonNavigatableSection', but there was a conflict on the PropertyType alias 'umbracoRedirect'. PropertyTypes must have a unique alias across all Compositions in order to compose a valid ContentType Composition.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[InvalidCompositionException: InvalidCompositionException - ContentType with alias 'Page' was added as a Compsition to ContentType with alias 'NonNavigatableSection', but there was a conflict on the PropertyType alias 'umbracoRedirect'. PropertyTypes must have a unique alias across all Compositions in order to compose a valid ContentType Composition.] Umbraco.Core.Models.ContentTypeCompositionBase.AddContentType(IContentTypeComposition contentType) +642 Umbraco.Core.Persistence.Repositories.ContentTypeQueryMapper.MapContentTypeChildren(IContentTypeComposition[] contentTypes, Database db, ISqlSyntaxProvider sqlSyntax, TRepo contentTypeRepository, IDictionary2 allParentContentTypeIds) +1032 Umbraco.Core.Persistence.Repositories.ContentTypeQueryMapper.GetContentTypes(TId[] contentTypeIds, Database db, ISqlSyntaxProvider sqlSyntax, TRepo contentTypeRepository, ITemplateRepository templateRepository) +306 Umbraco.Core.Persistence.Repositories.ContentTypeRepository.PerformGetAll(Int32[] ids) +659 Umbraco.Core.Persistence.Repositories.RepositoryBase2.GetAll(TId[] ids) +1610 Umbraco.Core.Services.ContentTypeService.GetAllContentTypes(Int32[] ids) +101 umbraco.controls.ContentTypeControlNew.SetupCompositionsPane() +260 umbraco.controls.ContentTypeControlNew.OnInit(EventArgs e) +178 System.Web.UI.Control.InitRecursive(Control namingContainer) +186 System.Web.UI.Control.InitRecursive(Control namingContainer) +291 System.Web.UI.Control.InitRecursive(Control namingContainer) +291 System.Web.UI.Control.InitRecursive(Control namingContainer) +291 System.Web.UI.

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.34248

Any help would be greatly appreciated.

Thanks :)