Use case: I enabled a module, without enabling the required module. I saved the configuration on the modules page and it showed me the following screen -
I clicked "Continue" and then I get the WSOD (blank page).
I added error reporting php code in my index.php in root directory. It showed a fatal error - Fatal error: Call to undefined function variable_realm_switch() in /mysite/sites/all/modules/i18n/i18n_variable/i18n_variable.module on line 54
I cannot go back to the admin pages to enable the required module, because of WSOD. Is there a way to enable the module from the code? I cannot delete the modules involved in this error, because I will end up losing the data associated with the modules.