If you find that the General Settings tab of slides in your Divi Theme slider modules are blank, the reason is likely to be that the site has been updated to WordPress 4.9, while still on an older version of Divi. WP 4.9 caused some issues with the color picker functionality used by Divi which resulted in display issues in the module settings. One such display issue is that the General Settings are hidden on slides within the slider module.
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​If you update to the latest version of Divi, that should resolve the issue. I'd suggest taking a backup prior to updating just in case you have any issues with the latest version.
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