My website is unable to load due to server error after upgrading my extensions for my site for an original problem created in k2 where i received the following error message when opening an item:

Calendar.setup: Nothing to setup (no fields found). Please check your code

(picture also attached)

Here is the error log after upgrading my extensions now that my website no longer loads:

[16-Jan-2012 10:23:24] PHP Warning: Missing argument 3 for plgContentJA_tabs::onPrepareContent() in /home2/legsbums/public_html/plugins/content/ja_tabs.php on line 83

[16-Jan-2012 10:23:24] PHP Fatal error: Call to undefined method K2ModelItemlist::hasChildren() in /home2/legsbums/public_html/modules/mod_jabulletin/helper.php on line 377

For Calendar.setup message : try to see these post in Joomla forum