I looked at the legend below the post list and found the cause.
Literal
Post-list [possessive-の] below [possessive-の] legend [object-を] see [and-て] cause [subject-が] understood.
投稿一覧 'post list.' 凡例 'legend, key' — the explanatory key on a chart or page. 原因が分かりました 'I understood the cause.' A simple troubleshooting success story from a forum context.