This is automatic translation (from Korean) of 19.4.2021 update notice for Korean server (we will probably get same at our next maintenance):

Good morning. This is Cal Online.
The following is the update on April 20 (Tue).

1) Resurrection Order of Resurgence, Magic Vacancy Stone Change

-The Resurrection Order of Resurgence, Magic Gong Stone has been modified so that it can be destroyed.

2) Mission document item change

-Mission document items have been modified so that they can be stacked.

3) Catapult's leverage, undead essence drop rate adjustment

-The drop rate of the catapult's leverage and the undead's essence has been increased.

4) Choongmugong event wood item drop rate adjustment

-The drop rate of the Choongmugong event wood item has been increased.

5) Monster bleeding debuff system message error correction

-Corrected text displayed incorrectly when applying bleeding debuff from monsters.

6) Correction of errors in the lawless zone of the dead (reported by Woo Soo-young, killer user)

-Fixed a problem where monsters were summoned in the wrong location in the area of ​​the dead's lawless zone.

7) Attack power boost order book store update

-For more information, please refer to the event page.