This patch is mainly focused on balance changes, no bug fixes are mentioned in the patch notes. Tranquil boots item has been been reworked, Keeper of the Light and Drow Ranger nerfed and Living Armor has also received changes. You can check details below!
DotA 6.77c Changelogs (Patch Notes):
- Tranquil Boots disabled speed reduced to 25
- Tranquil Boots heal increased from 170 to 250
- Tranquil Boots cooldown increased from 40 to 60
- Tranquil Boots heal duration increased from 10 to 20
- Illuminate manacost increased from 150 to 150/160/170/180
- Illuminate AOE reduced from 400 to 350
- Spiked duration reduced from 2.75 to 2.25
- Spiked Carapace cooldown increased from 14 to 23/20/17/14
- Marksmanship bonus is removed when there are nearby enemy heroes (instead of just being halved)
- Reduced Marksmanship enemy aoe reduced from 400 to 375
- Heaven’s Halberd's Disarm is no longer dispelled by Manta
- Living Armor damage reduction is now done for all instances of damage that reduce its charges
It's surprising that there are no bug fixes done in this update or may be IceFrog forgot to put them in the changelogs. Anyway, you can now play the balanced new map. Also, the new series v6.78 will be arriving soon, keep checking DotA-Utilities for updates.