I had to delete and remove any reference to the sitting rug I did couse caused weird crashes , I still having crashes but less than befoure ...

You could try making the PC temporarily AI-controlled in a quest alias, and make an AI for "SitTarget" that targets the crosslegged sit item (Make the rug an activator, with the sit crosslegged item as a property.) - once the player is sitting, clear the alias so he can stand up again when he wants to.

I would suggest using the method Amethyst Deceiver explained (splicing your rug mesh into an existing furniture NIF & renaming the file). It probably didn't work for you because rugs don't have collision - you'd have to splice in another NIF's collision so Player has something to 'touch'.

Trying a trigger box with that script as-written probably wouldn't have worked either. I think you need to change the "onActivate" to "onTrigger"; OR you could create a primitive collision box which is set to activate the furniture (like Vanilla mannequins have).

I just found a very simple way to get the player-avatar to sit cross-legged.
.
I start by placing the BlessingKneelMarker from the Furniture object group. I open the base object form and rename it so that I can create a new form and relabel the toggle to something like "Sit cross-legged" instead of "Altar of Dibella". Halfway down the left side of the base object form is the keyword list. From this, I remove the isIdleBlessingKneel Keyword and add the isSitCrossLegged Keyword.
.
In-game, the player avatar can activate this as if it were the BlessingKneelMarker - but instead of kneeling, the isSitCrossLegged Keyword forces the avatar to sit cross-legged. A script to center this marker on (or offset this marker from) your rug -once deployed- will likely do the trick...

can u make and upload? ...

.
What I'm up to so far is just getting the player to sit cross-legged on a pre-placed static such as a rug. To demonstrate, I've set a basic picnic on what looks like an ideal fishing spot located just to the left of the bridge across the river from Riverwood. This is actually located in the "Riverwood Bridge" exterior cell (Tamriel), and the key furniture marker is zqzzFlSitCrossLegged.
.
The Plug-in fragment, just to demonstrate, is http://realmeleven.net/1011_%28Skyrim%29_RiverwoodFishingPicnic.esp. [EDIT]Save Link As... to download[/EDIT]
.
I found that removing the FurnitatureForce3rdPerson Keyword allows the player to look around while seated and it is very easy for the player to switch between third and first person views if they set up all their controls. I hope you find this useful...

I can0t find anything next to the bridge ...

actually it doesnt load it and says the file is not a valid tes file ...

For a more exact location (From Riverwood; North bank of the River, Just West of the bridge):
.
[img]http://realmeleven.net/PicnicBlanket.GIF[/img]
.
I'm getting the same problem too.
.
Let's try this from as a standard zip archive served by a basic http://realmeleven.net/LD-1011-ES5-PicnicBlanket.htm.
.
That seems to do the trick - I hope it works for you too.

Two tries and two crashes when loading ... something wrong in the file?

I am sorry to hear that the plug-in is not working correctly on your system.
.
I wanted to see if the method of file serving was still introducing problems. So I just downloaded the zip archive via the link, scanned the zip archive with AVG, opened the zip archive and transferred the plug-in from the zip archive to the Skyrim Data directory (overwriting the existing variant of the plug-in). When I ran the game, I turned off the other all the other plug-ins and started only with this one. In my case there was no crash and the plug-in functioned correctly.
.
Did you check the load order?

Perhaps the problem is there's an ESP but no scripts? or does it use all standard vanilla scripts?

I checked it out and the picnic spread is there in my Riverwood bridge area...oddly, the basket is floating up in the air, but I can at least sit down on the rug by clicking the food and drink items.

Did you make a custom object, or did you figure out a way to make players use arbitrary furniture?

Make a new trigger box and add this script:

Scriptname TEST Extends ObjectReferenceEvent OnTriggerEnter(ObjectReference akActionRef)	 Debug.SendAnimationEvent(akActionRef, "IdleSitCrossLeggedEnter")EndEvent

Or you can use an activator:

Scriptname TEST Extends ObjectReferenceEvent OnActivate(ObjectReference akActionRef)	 Debug.SendAnimationEvent(akActionRef, "IdleSitCrossLeggedEnter")EndEvent

.
1. It sounds like I stuffed up the L_Prop box - and food + drink positions could probably do with improving
2. No custom object - just an invisible furniture marker which I found the player actually could interact with. I swapped the keywords in the base object so that activating it would make the player sit cross-legged instead of doing the kneeling worshiper thing. Shamelessly plagiarizing myself:
.
I start by placing the BlessingKneelMarker from the Furniture object group. I open the base object form and rename it so that I can create a new form and relabel the toggle to something like "Sit cross-legged" instead of "Altar of Dibella". Halfway down the left side of the base object form is the keyword list. From this, I remove the isIdleBlessingKneel Keyword and add the isSitCrossLegged Keyword.
.
In-game, the player avatar can activate this as if it were the BlessingKneelMarker - but instead of kneeling, the isSitCrossLegged Keyword forces the avatar to sit cross-legged.
.
[EDIT]No scripts are required to make this work as it does now[/EDIT]

Thank you RealmEleven! I've been looking for a way to make NPCs sit crosslegged and that worked like a charm. I know this was intended for the player character's use, but I couldn't figure out an alternative to force
NPCs to squat down.

ah wait so its a CK feature tohe calling of the animation and is not embedded in the nif , then I guess you could use any nif just replacing the ani there?

well he swapped out a keyword...the CK apparently uses keywords to affect a lot of things (for example, putting a keyword of BeastRace on the player makes it use the "Claw swipe" animation when attacking unarmed)