The Unknown Wall
Scholars have indicated that seeing an unknown wall that has been weakened or breached, allowing thieves or wild animals to enter, might signify a weakening in the affairs of Islam or knowledge in that place. It could also point to a flaw in the pillars of religion, or corruption affecting the dreamer's faith, wealth, or what protects them from harm.
Per Ibn Sirin's Muntakhab al-Kalam fi Tafsir al-Ahlam