Attribute vector 'Title' not available for sorting.
This error occurs while trying to apply sort using APIs to sort a column which is not enabled for sorting on Search schema.
Navigate to Search Administration on Central Administration and select Search Schema.
Select the Managed Property that you are trying to use for sorting.
Now click on this Managed property. This opens the 'Edit Managed Property' page.
Now scroll down until you reach the section on Sorting. Ensure that this is set to 'Yes- active' as shown in below screenshot, which allows the value to be sortable immediately after a full crawl.
'Yes - latent' option allows the value to be made sortable at a later period of time by selecting 'Yes - active' without requiring a full crawl.