how do I change the child theme name in multisite?

I crashed wp-admin and my multisite! I have network activated parent theme "FrameMarket" (and also activated Gallery theme). I would like Gallery to be the child theme. In network admin settings, in that long page of text fields, I replaced "Gridmarket" with "Gallery" in the child theme text field. Saved changes. Result was a total crash, leaving debug errors:

Warning: require(/www/wordpress/wp-content/themes/framemarket/inc/theme-options.php): failed to open stream: No such file or directory in /www/wordpress/wp-content/themes/gallery/functions.php on line 358

Fatal error: require(): Failed opening required '/www/wordpress/wp-content/themes/framemarket/inc/theme-options.php' (include_path='.:disappointed:usr/share/pear') in /www/wordpress/wp-content/themes/gallery/functions.php on line 358

I cannot use wp-admin to change this one word back. I can use ftp to access wordpress files - which file can I update to fix this?