Scheduled Updates fail with ERROR: "Failed to execute data source query. ---> Spotfire.Dxp.Data.Exceptions.ImportException: Failed to open data source."

Scheduled Updates fail with ERROR: "Failed to execute data source query. ---> Spotfire.Dxp.Data.Exceptions.ImportException: Failed to open data source."

Analysis files added in Scheduled Update fail to load with the error "Failed to execute data source query for data source "XXXX". Refer to thee attached error screenshot (Scheduled_Update_Failed.JPG) under Overview tab in Scheduling & Routing.

You can also see the error below in the Web Player logs:
----------------
ERROR;2017-05-03T18:02:21,243+02:00;2017-04-27 16:02:21,243;881c811b-c7f4-46dc-9278-19a338150676;2616314a7cLeUP;WorkThread 63;SPOTFIRESYSTEM\scheduledupdates;TSSPUNE\svc-Spotfire;Spotfire.Dxp.Web.Library.ScheduledUpdates;"Load of '/Test/development/Web_Player_Monitoring ff6d2993-c517-473f-adda-0dea909a02ab' (ff6d2993-c517-473f-adda-0dea909a02ab) failed (JobDefinitionId=b79aa92a-1b9a-43b3-abf9-a66a6b6acea9, JobInstanceId=61f54882-30b5-49a4-a723-a7b840a46bc3)"

System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. --->
System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. --->
Spotfire.Dxp.Data.Exceptions.ImportException: Failed to execute data source query. --->
Spotfire.Dxp.Data.Exceptions.ImportException: Failed to open data source. --->
Spotfire.Dxp.Framework.Library.LibraryException: Library entry with id=d1ec4e3d-4f3f-45fe-9252-194d73bfda5d does not exist.
------------------- This error is because the scheduled update user "scheduledupdates@SPOTFIRESYSTEM" does not have "Access" permission on the Spotfire Library folders where the following  items are located:

- Library item with ID mentioned in above error (e.g. Library entry with id=d1ec4e3d-4f3f-45fe-9252-194d73bfda5d does not exist.)
- The information links
- Any elements used in building the information link (column elements, filter elements, join elements)
- Spotfire data source(s) used in creating any of the elements used in building the information link

Note that you can search missing library item with id, e.g., "d1ec4e3d-4f3f-45fe-9252-194d73bfda5d" in Spotfire Library using Library Administration Window in Spotfire Analyst Client as follows.

- Login to Spotfire Analysts Client as Spotfire Admin or Spotfire Library Administrator.
- After login, go to Tools ---> Library Administration
- Here in Library Administration Window, there is a search box on the top right corner.
- To search library item with ID, you need to put search like this in search box- 
Example> id:d1ec4e3d-4f3f-45fe-9252-194d73bfda5d https://docs.tibco.com/pub/spotfire_server/7.7.0/doc/html/TIB_sfire_server_tsas_admin_help/GUID-3668E614-5DAC-40D8-B447-E886FCDE0839.html