Wordpress database error Table 'wordpress.wp_network_terms' doesn't exist

Hi,

We get this error:

WordPress database error Table 'wordpress.wp_network_terms' doesn't exist for query SELECT term_id FROM wp_network_terms WHERE name = 'giftcard' AND slug = 'giftcard' AND term_group = 0 made by do_action_ref_array, call_user_func_array, postindexercron->process_rebuild_secondpass, postindexermodel->index_tax, postindexermodel->insert_or_get_term

We have searched the web and found only a couple of links of people with the same problem.

We have removed and re-installed post indexer, rebuild index and still get the errors.

Any ideas why this happens and how it can be fixed?

Thanks.