WowAce

Did multiple tests today for over an hour. Seems bartender is causing serious lag spikes on my wow TBC client. Friends of mine that also use have confirmed it as well. Please fix ;)

yes i am also having this problem, on tbc wow, and have isolated it to bartender4. i have noticed it happens the worst when doing the bombing run in ogri'la, for what it's worth.

Can confirm. Bartender is causing microfreezes/stuttering whenever other players load in on your screen. Very noticeable when flying around in Shattrath. Every time you come close to Aldor bank the game will microfreeze/stutter for a bit just as all the players show up. At least on Firemaw with a large number of people there. If I disable Bartender the game runs smooth as butter.

Can confirm all above posts, i've isolated the issue to bartender4, it only occurs whenever a great number of players are around in any given area.

I am also having this problem in TBC only happens in player crowded areas. Or after casting a spell such as invis and players load back in.

After some testing, I'm pretty sure this is caused by lines 659 and 717 in Bartender4\libs\LibActionButton-1.0

The client gets hammered by dozens of "UPDATE_SHAPESHIFT_FORM" events when you enter an area with many players. (I counted almost 50 exiting the Stormwind bank with /etrace.)

This causes Bartender, at line 717, to attempt to update every button, once per incoming event. This results in several thousand button updates at once, which are what causes the stutter. For example, just exiting the bank in Stormwind causes me to receive over 6000 button updates.

A rough fix for this is to simply delete line 659, so the addon is no longer capable of reading the event causing trouble. This will probably break bar updates when shapeshifting. Someone can make a better fix than this, I'm sure -- probably read CLEU to determine when the player shifts? Or figure out if this event is even necessary? I don't have a druid to test, but UPDATE_BONUS_ACTIONBAR is supposed to fire once whenever the player stance/shapeshift changes, so that could be a suitable replacement.

UPDATE_SHAPESHIFT_FORM is only supposed to fire when the *player's* shapeshift form changes. Did Blizzard break something else with last week's hotfix for druids being stuck in form? https://us.forums.blizzard.com/en/wow/t/bugtbc-stuck-in-druid-forms/1206008/151

Great find @seppala.
UPDATE_SHAPESHIFT_FORM is definitely the problem, and it starting after the hotfix to druid shapeshifting seems about right. Blizzard definitely broke something.

After further testing I've noticed that the microstutters happens even with NO addons enabled, it's just much worse with Bartender enabled.

Here's a short video I recorded showing it with no addons enabled.
https://youtu.be/enqkUGYnr7w

I don't have access to the US forums, but if someone could post about this problem in the thread seppala linked, that would be great.

Yeah, I would expect the default UI to stutter as well, because there's a similar bit of code relying on the same event in Blizzard's UI. 

https://github.com/tomrus88/BlizzardInterfaceCode/blob/master/Interface/FrameXML/ActionBarController.lua

	if (   event == "UPDATE_SHAPESHIFT_FORM" 
		or event == "UPDATE_SHAPESHIFT_FORMS" 
		or event == "UPDATE_SHAPESHIFT_USABLE" ) then
		StanceBar_Update();
	end

another one in for this issue. I noticed it, thought it was a driver issue or a rogue setting. Disabled addon by addon and discovered bartender4 causing the issue. or at least amplifying one to the point it's super noticeable 

Literally experiencing the same thing as everyone else above! I have been having the worst stutters the past few weeks. It doesn't just happen in crowded areas, it happens in dungeons as well! I've checked every addon and Bartender is for sure the root of the frame stutters. Please fix it. I depend on your addon, I've used it since Wrath. Please!

Deleting 659th line in Bartender4\libs\LibActionButton-1.0 helped so far. I guess doing so breaks addon only for druids? Because stealth and stance bars still working fine.

Still no update or acknowledgement of this issue? Still ongoing. Still very bothersome.. Are there any other bar addons alike bartender that are not having this issue? I hate to say it but even though I've been using Bartender for easily a decade.. I might have to consider moving on if this issue isn't fixed or at the very least acknowledged as an issue or being worked on. Throw us a bone here? please?

The problem is with the game itself. Complete radio silence from Blizzard despite numerous reports.

Bartender making it worse is fixed by deleting line 659 and 717 in the LibActionButton file like explained in the posts above.

As of sunwell release removing the lines does not correct the issue. Sad to say after many, many years I have moved on from bartender to dominos.

Commenting out line 659 in Bartender4\libs\LibActionButton-1.0 seems to have resolved the issue for me. I don't play a Druid though.

I'm having this issue as well, and it's still going on. Do we know if there is a fix coming or someone is working on this? I saw someone say it was Blizz's problem, but it sure seems like a Bartender problem when I disable Bartender and it stops. Please help!

I have found a fix to this issue! Go to curse and download an addon called Dominos and replace Bartender as your UI/Actionbar addon! No more lag spikes!

In all seriousness though... It really sucks that is has come to this. I was living with the issue when I was on Myzrael because I really do like Bartender over all other addons.. But when I xfered to Atiesh.. I could no longer ignore it as the problem was worsened due to the increase of players. I had to find a solution.. and unfortunately finding another addon was that. Dominos doesn't seem to exhibit the same framerate stutter issue bartender has. And while, yeah, I understand that the root cause of this issue is blizz's fault.. Couldn't you issue a workaround until that is fixed? or acknowledge there is a problem and let us know you're working on it instead of conceding to "It's blizz's fault.."

You served me well over the many years I've used you, Bartender.. but I can't keep using you and sacrificing my gameplay experience. I'll check back when the issue is resolved. Hope it's sooner rather than never. 

Does this mean it's fixed? Can we return to using Bartender?

Edit: It's fixed, we no longer have to edit the LUA file ourselves after every update/install. Thank you!

Sadly the underlying issue with the game still exists, even on Wotlk beta (early beta was horrible. So much stutter with the UPDATE_SHAPESHIFT_FORM event spam when walking to the gear vendors in Dalaran since there were so many players there), but at least Bartender doesn't make the problem worse anymore.