TinyTds::Error: Invalid length parameter passed to the LEFT or SUBSTRING function

This is an update statement - which throws the below error when executed . I haven't used LEFT or Substring hence cannot understand what the error means

TinyTds::Error: Invalid length parameter passed to the LEFT or SUBSTRING function.: EXEC sp_executesql N'UPDATE [table] SET [status_description] = N''Completed successfully'', [status] = N''completed'', [updated_at] = ''2017-05-18T02:33:13.387'' WHERE [table].[id] = 23344; SELECT @@rowcount AS AffectedRows'

The table gets updated though