Rtm activity table does not exist error

**Hi I have been developing web sites in ASP.Net and core PHP, or have been converting contents of running wordpress sites to PHP and ASP.Net.

Now I have to maintain a wordpress site which was running fine until a few days ago. The sites stops working everyday and I have to manually restart WAMP server on our VPS. The error when accessing the site says “Error while establishing database connection”. When I checked the log, it was saying something like this: [08-Jan-2016 05:29:06 UTC] WordPress database error Table ‘mak_ivu.mak_rt_rtm_activity’ doesn’t exist for query SELECT activity_id from mak_rt_rtm_activity ORDER BY activity_id DESC limit 1 made by require_once(‘C:\sites\makivu\makivu.org\wp-admin\admin.php’), do_action(‘admin_init’), call_user_func_array, RTMediaActivityUpgrade->add_admin_notice, RTMediaActivityUpgrade->get_pending_count, RTMediaActivityUpgrade->get_last_imported

[08-Jan-2016 05:29:06 UTC] WordPress database error Table ‘mak_ivu.mak_rt_rtm_activity’ doesn’t exist for query SELECT count( DISTINCT activity_id) as pending from mak_rt_rtm_media where activity_id NOT IN( SELECT activity_id from mak_rt_rtm_activity ) AND activity_id > 0 made by require_once(‘C:\sites\makivu\makivu.org\wp-admin\admin.php’), do_action(‘admin_init’), call_user_func_array, RTMediaActivityUpgrade->add_admin_notice, RTMediaActivityUpgrade->get_pending_count

This means that a table mak_rt_rtm_activity must be thee in the wordpress database which is not there as I have checked manually. Please help me how to fix this error. Regards