Issue
You may notice that your hostserver log file is filled with error messages relating to your SharePoint group providers which are unable to resolve.
"GroupProvider.GetGroup - 64005 Failed to resolve [SPGroupProvider] - The remote server returned an error: (401) Unauthorized"
Error Code
--- End of inner exception stack trace ---","anonymous","0.0.0.0","ZAJNBSCDAPP11N2:C:Program Files (x86)K2 blackpearlHost ServerBin","714658724","c724d5e7ea8a4283a3a68aa5eb094d49",""
"714658725","2021-07-23 14:49:32","Error","IdentityService","64005","ResolvingException","IdentityService.ProviderCacheIdentity:GroupProvider.GetGroup","64005 Failed to resolve 'SP:Data PlatformDataPlatform Owners': The remote server returned an error: (401) Unauthorized..","anonymous","0.0.0.0","ZAJNBSCDAPP11N2:C:Program Files (x86)K2 blackpearlHost ServerBin","714658725","c0ab44f8c4234bbfa3576283fbce3f3d",""
"714658734","2021-07-23 14:49:32","Error","General","0","ErrorMessage","1","0 SharePointRoleProvider.GetGroups: System.Reflection.TargetInvocationException: An unexpected failure was encountered when contacting SharePoint to get information from the group provider Data Platform: The remote server returned an error: (401) Unauthorized. ---> System.Exception: The remote server returned an error: (401) Unauthorized.
at SourceCode.SharePoint15.Client.CSOMFunctions.GroupFunctions.LoadGroup(Group group, Boolean throwException)
at SourceCode.Security.Providers.SharePoint.Shared.SPCsomClient.SourceCode.Security.Providers.SharePoint.Shared.ISPGroupProviderClient.GetGroup(String groupName)
Resolution
Verify that the SharePoint URL's are active and functioning. If they are not, you can safely remove them, which will eliminate a lot of the errors being logged in the HostServer log.
You can find the SharePoint group providers in Management > Users > SP. When you click on SP, you will see a list of group providers.
Additional Information