Undefined index: custom_settings

I receive the following two errors after performing a search query:

Notice: Undefined index: custom_settings in apachesolr_multilingual_apachesolr_query_alter() (line 391 of .../apachesolr_multilingual/apachesolr_multilingual.module).

Notice: Undefined index: custom_settings in apachesolr_multilingual_form_apachesolr_search_custom_page_search_form_alter() (line 469 of .../apachesolr_multilingual/apachesolr_multilingual.module).

The first error occurs because there is no check to see whether $search_page['settings']['custom_settings'] is set (error at 391). Similarly, the second error is related because 'custom_settings' is not set at the check $search_page['settings']['custom_settings'] on line 469.

Within the last few months, function apachesolr_multilingual_apachesolr_query_alter($query) was rewritten. The previous version did not have this problem.

Note: I have 7.x-1.x-dev (April 11) installed for both apachesolr and apachesolr_multilingual.