SEARCH API + VIEW to search members I have a website in Drupal version 7.28. I have page where i want to search members by using Search option created from VIEW. It goes like this after submission:

https://domain.com/search-members?search_api_views_fulltext=anything

This page and functionalty was working fine few days back but not now. Page is blank without any error. There is result in database.

I can understand above info might not be sufficient to help but my only question is:

What can cause a blank page without an error? Possible problems? 

Here is the updated ERROR MSG: 

PDOException: SQLSTATE[42S02]: Base table or view not found: 1146 Table 'aeeee01_drpl21.search_api_db_user_index_field_business_phone' doesn't exist: SELECT COUNT() AS expression FROM (SELECT 1 AS expression FROM (SELECT t. FROM {search_api_db_user_index_field_business_phone} t WHERE (word = :db_condition_placeholder_0) UNION ALL SELECT t.* FROM {search_api_db_user_index_field_city} t WHERE (word = :db_condition_placeholder_1) UNION ALL SELECT t.* FROM {search_api_db_user_index_field_country} t WHERE (word = :db_condition_placeholder_2) UNION ALL SELECT t.* FROM {search_api_db_user_index_field_department} t WHERE (word = :db_condition_placeholder_3) UNION ALL SELECT t.* FROM {search_api_db_user_index_field_first_name_} t WHERE (word = :db_condition_placeholder_4) UNION ALL SELECT t.* FROM {search_api_db_user_index_field_job_institution} t WHERE (word = :db_condition_placeholder_5) UNION ALL SELECT t.* FROM {search_api_db_user_index_field_job_title} t WHERE (word = :db_condition_placeholder_6) UNION ALL SELECT t.* FROM {search_api_db_user_index_field_last_name} t WHERE (word = :db_condition_placeholder_7) UNION ALL SELECT t.* FROM {search_api_db_user_index_field_member_advisor} t WHERE (word = :db_condition_placeholder_8) UNION ALL SELECT t.* FROM {search_api_db_user_index_field_specialization} t WHERE (word = :db_condition_placeholder_9) UNION ALL SELECT t.* FROM {search_api_db_user_index_field_state} t WHERE (word = :db_condition_placeholder_10) UNION ALL SELECT t.* FROM {search_api_db_user_index_field_zip_code} t WHERE (word = :db_condition_placeholder_11) UNION ALL SELECT t.* FROM {search_api_db_user_index_name} t WHERE (word = :db_condition_placeholder_12) ) t GROUP BY t.item_id) subquery; Array ( [:db_condition_placeholder_0] => mlang [:db_condition_placeholder_1] => mlang [:db_condition_placeholder_2] => mlang [:db_condition_placeholder_3] => mlang [:db_condition_placeholder_4] => mlang [:db_condition_placeholder_5] => mlang [:db_condition_placeholder_6] => mlang [:db_condition_placeholder_7] => mlang [:db_condition_placeholder_8] => mlang [:db_condition_placeholder_9] => mlang [:db_condition_placeholder_10] => mlang [:db_condition_placeholder_11] => mlang [:db_condition_placeholder_12] => mlang ) in SearchApiDbService->search() (line 928 of /home1/aeeee01/public_html/sites/all/modules/search_api_db/service.inc).
You can look into this : 
https://api.drupal.org/api/drupal/includes!database!database.inc/function/db_query/7#comment-7019

https://api.drupal.org/comment/51338#comment-51338

https://api.drupal.org/comment/16974#comment-16974

And check if you made change in your taxonomy vocabulary, deleting any fields that the search would index in the views. 

You can also re-index your user.