What does this error mean:

2016-12-21 16:27:30,716 [www4][Thread:11][INFO] DotNetNuke.Services.Installer.Log.Logger - Manifest file finished successfully.

2016-12-21 16:27:30,872 [www4][Thread:11][FATAL] DotNetNuke.Web.Common.Internal.DotNetNukeHttpApplication - System.InvalidOperationException: Sequence contains no elements

   at System.Linq.Enumerable.First[TSource](IEnumerable`1 source)

   at Dnn.PersonaBar.Extensions.Components.Dto.PackageInfoDto..ctor(Int32 portalId, PackageInfo package)

   at Dnn.PersonaBar.Extensions.Components.InstallController.ParsePackage(PortalSettings portalSettings, UserInfo user, String filePath, Stream stream)

   at Dnn.PersonaBar.Extensions.Services.ExtensionsController.<>c.<ParsePackage>b__18_0(PortalSettings portalSettings, UserInfo userInfo, String filePath, Stream stream)

   at Dnn.PersonaBar.Extensions.Services.ExtensionsController.<>c__DisplayClass36_1.<UploadFileAction>b__1(Object <state>)

   at System.Web.LegacyAspNetSynchronizationContext.CallCallbackPossiblyUnderLock(SendOrPostCallback callback, Object state)

Comes from this https://github.com/juvander/DotNetNuke-Forum/blob/05.00.07_DNN8/branches/DNN_5/DNN_Forum.dnn

Works just fine in DNN8, but fails with DNN9, any hint what is wrong with the manifest?

Still no luck.

When viewing sites there is also this error in the log:

2016-12-23 07:27:14,251 [RD00155D573915][Thread:7][ERROR] Dnn.PersonaBar.Sites.Services.SitesController - System.NullReferenceException: Object reference not set to an instance of an object.

   at Dnn.PersonaBar.Sites.Components.SitesController.FormatPortalAliases(Int32 portalId)

   at Dnn.PersonaBar.Sites.Services.SitesController.GetPortalDto(PortalInfo portal)

   at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()

   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)

   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)

   at Dnn.PersonaBar.Sites.Services.SitesController.GetPortals(Int32 portalGroupId, String filter, Int32 pageIndex, Int32 pageSize)