Clicky Bug
 

Rev 974 w/ PEQ 946

Had a 10-dose blood of the wolf (14534) in the 1st slot in inventory (top left).
right clicked on it w/o a target and the spell completes casting and i get

'You must first select a target for this spell!'
Your spell is interrupted.

and get stuck in 'casting' mode - all spell icons greyed out, can't manipulate inventory, can't camp ('you can't use that command while casting')

I can sit and crouch (though they don't cancel/interrupt), can /q out or zone to fix it.

Seems to happen only with 'targetable' clicky (tried 10-dose potion of antiweight too (14540)).

Although an exception to this is Crystaline Silk Net (25648), which reports 'you must first select a target for this spell'
Your spell is interrupted

but doesn't go through the casting nor lock you into 'casting' mode.

'must equip' clicky's seem to work properly (Fabled Earring of Celestial Energy (76196)), as do 'inventory/equip' clicky's that are self-only (Circlet of Shadows (29400))

Guessing this is on the SoF client?

Yea - I said everything else except that ;)