Intermittent, unexpected "you are already casting a spell"

ForeverFun

Using chain lightning, the lightning hits the targets, the damage registers.

Try casting chain lightning again, to same target, sometimes get a failed case "you are already casting a spell".

I'm not already casting a spell at the time of the failed cast.

You can see that error twice in a row after the first successful cast, too.

It seems this has started happening recently, perhaps coincident with the "use object" related changes for potions/held spells?

Desired result: back-to-back spells cast reliabily when meeting FCR and FC guidelines.

Arnold7

I get this message at least a few times when it gets really busy.  I try to cast a spell only to get the message I am already casting one.  Always thought UO just could not keep up in real time with the action.  Really, think servers really are struggling to keep up when it gets busy.  The other night in the Void when I was alone the game kept playing the Void battle after it said the battle was lost.