SharePoint connection issues - (503) Server Unavailable


Since last week we're receiving feedback that loading Documents can be challenging. In the connections, we see that SharePoint is having issues to return information which is needed to list all libraries (see log below).

Unfortunately, these issues are related to SharePoint. We understand that you want to rely on a good stable connection so we have contact with Microsoft about the issue and are monitoring the situation closely. 

2020-03-23 10:25:09.003 ERROR [82]  NDAW.Html.Front.Workspace365MvcApplication - Unhandled error occurred in Html.Front 
 NDAW.Html.Front.Workspace365MvcApplication.Application_Error(:0) (null) 
 System.Net.WebException: The remote server returned an error: (503) Server Unavailable.
   at System.Net.HttpWebRequest.GetResponse()
   at Microsoft.SharePoint.Client.SPWebRequestExecutor.Execute()
   at Microsoft.SharePoint.Client.ClientRequest.ExecuteQueryToServer(ChunkStringBuilder sb)
   at Microsoft.SharePoint.Client.ClientContext.ExecuteQuery()
   at NDAW.Core.SharePoint.RecentDocumentsQuery.GetLastModifiedDocumentsForUser(Int32 numberOfItems)
   at NDAW.Html.Front.Workspace.LiveInformation.Documents.DocumentsLiveInformationController.ListLastModifiedDocuments()
   at lambda_method(Closure , ControllerBase , Object[] )


Update 24-03-2020 08:54 CET:
We are in close contact with Microsoft. They have changed some throttling rules, because of the high traffic load on their end. These changes are not announced specifically. During the wait, it could be that some sites are displayed again, or missing. Microsoft is doing diagnostics from their end as well. When we have more information, we will report it back to you.