i use a theme from fieldthemes but when i wanna see my shop, errors comes. 

(1/1) ContextErrorException

Notice: Trying to access array offset on value of type null

in 35655e6409b6198f29dd6e732ef9598dec599880_2.module.psshoppingcartpsshoppingc.php line 142at content_6358a1f3bd8037_78170550(object(SmartyDevTemplate))in smarty_template_resource_base.php line 123at Smarty_Template_Resource_Base->getRenderedTemplateCode(object(SmartyDevTemplate))in smarty_template_compiled.php line 114at Smarty_Template_Compiled->render(object(SmartyDevTemplate))in smarty_internal_template.php line 216at Smarty_Internal_Template->render(false, 0)in smarty_internal_templatebase.php line 232at Smarty_Internal_TemplateBase->_execute(object(SmartyDevTemplate), null, null, null, 0)in smarty_internal_templatebase.php line 116at Smarty_Internal_TemplateBase->fetch(null, null, null, null, false, true, false)in SmartyDevTemplate.php line 40at SmartyDevTemplateCore->fetch()in Module.php line 2490at ModuleCore->fetch('module:ps_shoppingcart/ps_shoppingcart.tpl')in ps_shoppingcart.php line 116at Ps_Shoppingcart->renderWidget('displayTop', array('smarty' => object(SmartyDevTemplate), 'cookie' => object(Cookie), 'cart' => object(Cart)))in Hook.php line 1017at HookCore::coreRenderWidget(object(Ps_Shoppingcart), 'displayTop', array('smarty' => object(SmartyDevTemplate), 'cookie' => object(Cookie), 'cart' => object(Cart)))in Hook.php line 964at HookCore::exec('displayTop', array('smarty' => object(SmartyDevTemplate), 'cookie' => object(Cookie), 'cart' => object(Cart)), null)in smarty.config.inc.php line 167at smartyHook(array('h' => 'displayTop'), object(SmartyDevTemplate))in SmartyLazyRegister.php line 83at SmartyLazyRegister->__call('smartyHook', array(array('h' => 'displayTop'), object(SmartyDevTemplate)))in 9601800038334ef3ef1742a02bdf2456fa1c72b4_2.file.layout-both-columns.tpl.php line 139at content_6358a1f08f64b9_43980111(object(SmartyDevTemplate))in smarty_template_resource_base.php line 123at Smarty_Template_Resource_Base->getRenderedTemplateCode(object(SmartyDevTemplate))in smarty_template_compiled.php line 114at Smarty_Template_Compiled->render(object(SmartyDevTemplate))in smarty_internal_template.php line 216at Smarty_Internal_Template->render()in smarty_internal_template.php line 385at Smarty_Internal_Template->_subTemplateRender('layouts/layout-both-columns.tpl', null, 'beauty_home2layouts/layout-full-width.tpl', 0, 31536000, array(), 2, false, null, null)in smarty_internal_runtime_inheritance.php line 116at Smarty_Internal_Runtime_Inheritance->endChild(object(SmartyDevTemplate), 'layouts/layout-both-columns.tpl')in 7aac18dc9b05a9a09c1a6ae7c0a58a9acce12ace_2.file.layout-full-width.tpl.php line 42at content_6358a1f05e4740_26665310(object(SmartyDevTemplate))in smarty_template_resource_base.php line 123at Smarty_Template_Resource_Base->getRenderedTemplateCode(object(SmartyDevTemplate))in smarty_template_compiled.php line 114at Smarty_Template_Compiled->render(object(SmartyDevTemplate))in smarty_internal_template.php line 216at Smarty_Internal_Template->render()in smarty_internal_template.php line 385at Smarty_Internal_Template->_subTemplateRender('layouts/layout-full-width.tpl', null, 'beauty_home2layouts/layout-full-width.tpl', 0, 31536000, array(), 2, false, null, null)in smarty_internal_runtime_inheritance.php line 116at Smarty_Internal_Runtime_Inheritance->endChild(object(SmartyDevTemplate), 'layouts/layout-full-width.tpl')in 6fc87ecb299f04e80af5438b12242d409e9ced04_2.file.index.tpl.php line 32at content_6358a1f0252604_75128358(object(SmartyDevTemplate))in smarty_template_resource_base.php line 123at Smarty_Template_Resource_Base->getRenderedTemplateCode(object(SmartyDevTemplate))in smarty_template_compiled.php line 114at Smarty_Template_Compiled->render(object(SmartyDevTemplate))in smarty_internal_template.php line 216at Smarty_Internal_Template->render(false, 0)in smarty_internal_templatebase.php line 232at Smarty_Internal_TemplateBase->_execute(object(SmartyDevTemplate), null, 'beauty_home2layouts/layout-full-width.tpl', null, 0)in smarty_internal_templatebase.php line 116at Smarty_Internal_TemplateBase->fetch('index.tpl', null, 'beauty_home2layouts/layout-full-width.tpl', null, false, true, false)in SmartyDev.php line 40at SmartyDev->fetch('index.tpl', null, 'beauty_home2layouts/layout-full-width.tpl')in FrontController.php line 727at FrontControllerCore->smartyOutputContent('index.tpl')in FrontController.php line 709at FrontControllerCore->display()in Controller.php line 326at ControllerCore->run()in Dispatcher.php line 518at DispatcherCore->dispatch()in index.php line 28

what i should do? T____T