Check empty protection slots
Official notes say the raid-preparation screen warns about empty armor, helmet and flashlight slots when suitable gear is available in storage. A head covering without protection value counts as an empty helmet slot for this warning.
Practical use
Use that warning as the final step after choosing an objective and extraction plan. It catches omissions, but it does not choose a loadout for you or guarantee that a raid will be low risk.
Version note
This independently written guide summarizes current official update information. Check the live game client and official notes before making a high-risk decision, because live-service rules can change.
Independent guide based on supplied research and current official information.