Show locations switcher not saving when large data set present in db

Summary:
When a large number of countries, regions and cities exist in the geodir_post_locations table, selecting the option “show locations switcher in menu” does not save.

Reproduction steps:
– load the geodir_posts_location table with a lot of data
– login to admin panel and navigate to the multilocations tab of geodir
– select “Show Locations Switcher in Menu” option
– scroll down and save

Current results: blank white page on save
Expected results: for the option to be saved on save

Screenshots attached.