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https://nishantrana.me/2016/02/27/fixed-the-server-is-busy-and-the-request-was-not-completed-try-again-later-or-usersettings-with-id-does-not-exist-in-plugin-in-crm-2/
Fixed – “The server is busy and the request was not completed. Try again later” or “usersettings with Id = ‘’ does not exist” in Plugin in CRM 2013\2015