I get an error message in one of the site collections maintenance log:
01/15/2020 11:08:13.25 OWSTIMER (0x4F8C) 0x0DB0 SharePoint Foundation Upgrade SPFeatureDefinition aj2bj ERROR Feature upgrade action 'CustomUpgradeAction.RegisterEventReceiver' threw an exception upgrading Feature 'HubSite' (Id: 15/'b6b7e8b4-0207-4104-a0a9-606c826e5645') in Site 'https://tenantname.sharepoint.com/sites/sitename': Failed to create feature upgrade receiver object from assembly "Microsoft.SharePoint, Version=18.104.22.168, Culture=neutral, PublicKeyToken=71e9bce111e9429c", type "Microsoft.SharePoint.SPHubSiteFeatureReceiver " for feature "HubSite" (ID: "b6b7e8b4-0207-4104-a0a9-606c826e5645"): System.ArgumentNullException: Value cannot be null. Parameter name: type at System.Activator.CreateInstance(Type type, Boolean nonPublic) at System.Activator.CreateInstance(Type type) at Microsoft.SharePoint.SPCustomFeatureUpgradeAction.GetReceiverObject() 47742e9f-207b-a000-a831-0aca512664d9
I found out that 'b6b7e8b4-0207-4104-a0a9-606c826e5645' is a SharePoint 2019 feature. How did it get to SharePoint Online?
I have searched for the answers on the internet, but wasn't able to find any. And I don't have any idea how to fix it.
Can you help?
Your help is greatly appreciated.