When you use a skill, it takes SP like it normally does, but sometimes, after you wait for awhile, your SP goes down for no reason. That amount equal to the skill you used. It's like your skill cost twice the SP it needs.
Here's the video for demonstration
http://youtu.be/6jDjfWV2NKM

I don't know if this is game mechanism or something, but it's really annoying. As I'm already suffering from lack of SP, this make my SP deplete completely after 2 skills.

seems lag , sometimes happen to me too when i do multiple skill in quick sucession , so ussualy i make sure i have enough for combo first before strike...

This happens to me too when I use Rolling Thunder... However I can usually cancel that issue by casting another spell, for some reason i stops the SP drop later.

Whoa, I always thought it was lag by taking time to update the meter.
I do think that bug might be related to the skills having many hits... thought the last skill you used costed 86 mana and had 4 hits, if it consumed that ammount for each hit you wouldn't even be able to use it.

I'm relatively certain that this is caused by packets being dropped and arriving later than other ones =X

same as mine.

When I use Rainbow Peacock VII, SP cost 123 depleted my mana to 0
and When I use Lunge IV

Does anyone knows how to avoid this? I keep doing burst attack all at once Lunge Step V > Skill 1 > Skill 2 but there this times that my sp just drops to 0 after Lunge V eventhough I have enough sp for 3 skills. It annoys me so much that I can't even dodge and block at 0 sp because of this.

hmm Let pin down what we know/don't know yet....

1.This seem to happen to mutli weapon , so this mean it not an single weapon type

2.this affect more then one player, and seem to be always in same fashion type drops the user to 0 SP, after few cast.

So this mean an weapon/skill isn't truly bugged unless it always around the same type skill on the weapon for all of these.

Magatama's if you can list all the Magatama you are using we can narrow down if people are using at least one the same type magatama that could cause this.

trying see if it happen when you use only one skill , or it skill after skill. and see if one of those trigger it , and doesn't (so using 1 skill doesn't have any result mean a combo skill after skill trigger the event).

This is just flat info we can look at as of now and try to guess what causes it, and pinpoint what might be the cause of it.

I believe the cause of the bug is that

1. The game counts each part of the skill combo as a seperate cast of the skill, evidenced by how the cooldown timer is reset every time the combo is continued.
2. The SP cost is only incurred much later, implying that the server deducts SP for each part of the combo but the client does not. When the server tells the client that the SP you should have is much lower than what you actually have, you lose the SP that you didn't earlier.

There should be no relation to anything other than only happening to skills with more than one combo, aka those that don't give you the red flames above your HP and SP bars that progress with your right mouse button.

Otonashi wrote:I believe the cause of the bug is that

1. The game counts each part of the skill combo as a seperate cast of the skill, evidenced by how the cooldown timer is reset every time the combo is continued.
2. The SP cost is only incurred much later, implying that the server deducts SP for each part of the combo but the client does not. When the server tells the client that the SP you should have is much lower than what you actually have, you lose the SP that you didn't earlier.

There should be no relation to anything other than only happening to skills with more than one combo, aka those that don't give you the red flames above your HP and SP bars that progress with your right mouse button.

My observations are more or less in line with this. Some skills like Sacred Strike don't incur additional SP costs on subsequent hits, but skills such as Ice Blossom or Lunge Step seem to do it. Sometimes the deductions are made in time - this is likely when the server ends up resolving the deduction and the packet send during the window of execution. Usually, it is not made in time, so it gets deducted later when the timed loop finally checks the requests in the stack. It is especially noticeable when you switch weapons because I surmise it's receiving a status update during this time for the weapons.

What throws me for a loop is when the additional SP deduction doesn't happen. Current theory is that it doesn't happen if you miss with the subsequent hit(s), but I'm not sure (and there's always the likely possibility that the backend is not designed in an intuitive manner).