Also dont think that other template clubs are better check this out:
www.joomlart.com/forums/topic/ja-megastore-question/

Do you know what I have had to do to fix this error.
Developers has done nothing yet.
All the same. LOL!
P.S.
No piece of code is perfect and Smartaddons templates are beautiful.
Thank you Smartaddons!

hmmmm ok,

Dear Baroroloko,

We're updating the module k2 for K2 2.8.0
if you want to fix directly, please send us the information of your site in the website information for the admin box to check directly?

thanks

Help From Adam:

Please go to our module and edit the file: \modules\mod_sj_k2_extraslider\mod_sj_k2_extraslider.xml and find:

<field name="item" type="item" default="" label="K2_ADD_ITEMS" description="K2_USE_THIS_TO_ADD_ITEMS_TO_THE_LIST_BELOW"/>
<field name="items" type="items" default="" label="K2_DRAG_AND_DROP_TO_REORDER_ITEMS" description="K2_DRAG_AND_DROP_TO_REORDER_ITEMS_CLICK_THE_REMOVE_ICON_TO_REMOVE_AN_ITEM_FROM_THE_LIST"/>

=> change to:

<field name="items" type="k2modalselector" default="" label="K2_ADD_ITEMS" description=""/>

thanks ... and it's working!

Dear Sir,

If you have any the problem please contact us.

thanks

Hi Baroroloko,
Thank you very much!
We have similar problem with the mod_sj_k2_slider and with your changes in the xml file now it's working.
Great !