ISP:
Telekom

Type of Internet Connection:
DSL

Internet Connection Speed:
6mbit/s

Date & Time:
21:00ish till 21:31

Frequency:
Sometimes (reproduceable)

Character Name:
Favorite Eu

Race:
Miqo'te F

World:
Moogle

Class/Level:
L50 Bard

Area and Coordinates:
Binding Coil t2 and Whitebrim

Party or Solo:
Party (8 Member) and solo

NPC Name:
None

Monster Name:
ADS and Nodes, Striking Dummy, can be done on any mob

In-Game Time:
i dont know =( 20:00-21:00 ST

Steps:
While beeing in combat, executing Blunt arrow, the Skill goes on CD while it does neither do damage, not silencing and invisible on the Battle Tab.

It pretty much happened like this:
While beeing buffed (with whichever buff) on my brd, while using a skill, the blunt arrow execution goes off but the skill does not get registered, resulting in "missing" the silence.

I will add a video (easiest to reproduce with barrage)

Link