I've heard you like pity systems, here's the first and not the last one ~
(next one will be related to costumes)

Refinement-Pity-System

each time you fail at the refiner, your chance for your next attempt with same equipment type, level and refine will be increased
increase for every fail is 10% of base chance for refine level of up to +12, 5% of base chance after +12.
upon success on the unique combination of type, level, refine the bonus chance gets removed again
you can have mutiple bonus chances for various combinations at once
these pity attempts are saved per character
the UI always shows the correct chances (though 66.5% would be shown as 66% as they UI doesn't know decimals)

Events

entering events with no space in inventory will now be prohibited

Instances/Dungeons/Quests

Episode 19 quests with a daily cooldown now reset at 00:00 server time
Constellation Tower: treasure boxes can now be opened by everyone (not just party leader)
fixed an issue that allowed non-party leaders to create an instance in some locations
Bioresearch Laboratory: fixed incorrect behavior in the boss fight (this will make it easier to handle for melee classes)
Old Glast Heim Challenge Mode:
• fixed a bug that could cause Oscar to stay after the boss has been summoned
• 💡added a cooldown to the party teleport mechanic
• fixed safe enchanting of Temporal Headgears to deduct zeny

Items/Item handling

💡reduced SP potion cost in paramarket
fixed Episode 19 Clear Ticket to not have trade restrictions
💡Episode 17.1 Clear Ticket no longer has completion conditions
fixed One Eye Dollocaris Card to provide ghost elemental dmg instead of fire
fixed Treasure Mimic Card's combo bonus to scale with refine rate of garment
fixed Roses of Choice's weight
fixed some item descriptions
💡changed line enchant description "All elemental resistance" to "All elemental resistance (except neutral)"
fixed Star Gladiator Stone (Mid) to affect Hatred of the Sun Moon and Stars
fixed Upgrade Part - Plate's name (was Glove)
fixed Costume Fairy of Eden's alignment
💡 Old Papyrus is no longer trade restricted

NPC

fixed Tiara's element to be holy
fixed Wolf Card to be available as reward at Yufa's Roses exchange
fixed Dala to no longer list "All Class" shadow gear twice
Yufa:
• fixed to no longer list "Nihil Card" twice
• fixed exchange cost of Wolf Lugenburg Card
Special Fashion Shop: Category 6 has been added
💡Sandra can now convert these equipments to costumes:
• Dark Bacilium
• Shrine Maiden Hat
• Ancient Gold Ornament
💡Hwaran (Para Market) now sells Bloody Edge
💡Kaa (equipment crafting) can now create Polar Bear Cap and Romantic White Flower
💡Daily Boards will now tell you how many times you can get item rewards when you turn in the quest to get your rewards.

Donation Shop

added Costume Be My Friend Egg
added Costume Wild Long Hair Egg

Skills

fixed Blessing of Mystical Creatures' p.atk bonus
fixed Talisman Of Protection to recover AP
fixed Star Gladiator's day of Sun/Moon/Star mechanics to follow day of month (this information has been added to @time)
Acid Terror:
• fixed to increases base damage by 100% per level of Learning Potion
• fixed to deal halved damage to boss monsters
• fixed visual display of hits
Demonstration:
• fixed to be treated as melee skill
• fixed damage formula from ATK 200% to ATK 300% + Learning Potion Lv x 10% based on level 5

PvP / GvG

fixed WoE-TE PvP FFA room to allow TE items and apply flee reduction
general damage reduction from skills increased to 50%
WoE TE: enabled Box of Sunlight

Note: we're elaborating a way to get MuhRO PVP discussion / decisions going. Nothing is set in stone as of now.
Note2: remember that the WoE TE times are changed now (next WoE TE times are on Saturday and Sunday)

Other

fixed Weapons Size Penalty for Huuma Shuriken (75% damage vs Small/Medium) and 2h Mace (75% damage vs Small)
💡#map channels will now be joined automatically
fixed some quest descriptions
💡Players who move too far away from a monster they hit will no longer be eligible for rewards when another player kills the monster.
fixed Homunculi to continue receiving EXP when their master reached the EXP-gain-cap

Earlier changes (already live)

fixed refine chances for level 5 weapons / level 2 armors from 3->4 and 4->5 to be 90% and 70% (was 80% and 80%)

💡= community suggestion