Getting the following error - "This is a temporary issue, so try again in a few minutes."

[Abhinav_koli]

Hi,

While making rest api calls - I am getting above error with status code 503 adding 

rest Api  for reference -https:/sharepoint_url/_api/Web/Lists(guid'file_guid')/Items(id)/FieldValuesAsText.

Please help me to resolve this issue.