Bump. Experiencing same issue. Has to do something with module Google Analitics tracking. For me it happens at checkout step. In using 1.7.6.7 version with custom theme. Php version 7.2
(1/1) ContextErrorException
Notice: Array to string conversion
in HookDisplayFooter.php line 74
at HookDisplayFooter->run()
in ps_googleanalytics.php line 111
at Ps_Googleanalytics->hookDisplayFooter(array('smarty' => object(SmartyDevTemplate), 'cookie' => object(Cookie), 'cart' => object(Cart), 'altern' => 2))
in Hook.php line 970
at HookCore::coreCallHook(object(Ps_Googleanalytics), 'hookdisplayFooter', array('smarty' => object(SmartyDevTemplate), 'cookie' => object(Cookie), 'cart' => object(Cart), 'altern' => 2))
in Hook.php line 355
at HookCore::callHookOn(object(Ps_Googleanalytics), 'displayFooter', array('smarty' => object(SmartyDevTemplate), 'cookie' => object(Cookie), 'cart' => object(Cart), 'altern' => 2))
in Hook.php line 907
at HookCore::exec('displayFooter', array('smarty' => object(SmartyDevTemplate), 'cookie' => object(Cookie), 'cart' => object(Cart), 'altern' => 2), null)
in smarty.config.inc.php line 167
at smartyHook(array('h' => 'displayFooter'), object(SmartyDevTemplate))
in SmartyLazyRegister.php line 83
at SmartyLazyRegister->__call('smartyHook', array(array('h' => 'displayFooter'), object(SmartyDevTemplate)))
in 3cc5f078f09a6d6ed6265bba4a1ab6c944819596_2.file.footer.tpl.php line 115
at Block_14645850055f4ac055e15b08_80828159->callBlock(object(SmartyDevTemplate))
in smarty_internal_runtime_inheritance.php line 248
at Smarty_Internal_Runtime_Inheritance->callBlock(object(Block_14645850055f4ac055e15b08_80828159), object(SmartyDevTemplate))
in smarty_internal_runtime_inheritance.php line 184
at Smarty_Internal_Runtime_Inheritance->process(object(SmartyDevTemplate), object(Block_14645850055f4ac055e15b08_80828159))
in smarty_internal_runtime_inheritance.php line 156
at Smarty_Internal_Runtime_Inheritance->instanceBlock(object(SmartyDevTemplate), 'Block_14645850055f4ac055e15b08_80828159', 'hook_footer', 11)
in 3cc5f078f09a6d6ed6265bba4a1ab6c944819596_2.file.footer.tpl.php line 160
at Block_13563459485f4ac055e13d50_47003828->callBlock(object(SmartyDevTemplate))
in smarty_internal_runtime_inheritance.php line 248
at Smarty_Internal_Runtime_Inheritance->callBlock(object(Block_13563459485f4ac055e13d50_47003828), object(SmartyDevTemplate))
in smarty_internal_runtime_inheritance.php line 184
at Smarty_Internal_Runtime_Inheritance->process(object(SmartyDevTemplate), object(Block_13563459485f4ac055e13d50_47003828))
in smarty_internal_runtime_inheritance.php line 156
at Smarty_Internal_Runtime_Inheritance->instanceBlock(object(SmartyDevTemplate), 'Block_13563459485f4ac055e13d50_47003828', 'footer_main')
in 3cc5f078f09a6d6ed6265bba4a1ab6c944819596_2.file.footer.tpl.php line 31
at content_5f4ac055e17e17_20570834(object(SmartyDevTemplate))
in smarty_template_resource_base.php line 123
at Smarty_Template_Resource_Base->getRenderedTemplateCode(object(SmartyDevTemplate))
in smarty_template_compiled.php line 114
at Smarty_Template_Compiled->render(object(SmartyDevTemplate))
in smarty_internal_template.php line 216
at Smarty_Internal_Template->render()
in smarty_internal_template.php line 385
at Smarty_Internal_Template->_subTemplateRender('file:_partials/footer.tpl', null, 'layouts/layout-left-column.tpl', 0, 31536000, array(), 0, false)
in e715f760a3d91c84f22bd29f116ceacd21baa8fa_2.file.layout-both-columns.tpl.php line 397
at Block_17959379225f4ac055760520_82426645->callBlock(object(SmartyDevTemplate))
in smarty_internal_runtime_inheritance.php line 248
at Smarty_Internal_Runtime_Inheritance->callBlock(object(Block_17959379225f4ac055760520_82426645), object(SmartyDevTemplate))
in smarty_internal_runtime_inheritance.php line 184
at Smarty_Internal_Runtime_Inheritance->process(object(SmartyDevTemplate), object(Block_17959379225f4ac055760520_82426645))
in smarty_internal_runtime_inheritance.php line 156
at Smarty_Internal_Runtime_Inheritance->instanceBlock(object(SmartyDevTemplate), 'Block_17959379225f4ac055760520_82426645', 'footer')
in e715f760a3d91c84f22bd29f116ceacd21baa8fa_2.file.layout-both-columns.tpl.php line 110
at content_5f4ac055766f73_50118935(object(SmartyDevTemplate))
in smarty_template_resource_base.php line 123
at Smarty_Template_Resource_Base->getRenderedTemplateCode(object(SmartyDevTemplate))
in smarty_template_compiled.php line 114
at Smarty_Template_Compiled->render(object(SmartyDevTemplate))
in smarty_internal_template.php line 216
at Smarty_Internal_Template->render()
in smarty_internal_template.php line 385
at Smarty_Internal_Template->_subTemplateRender('layouts/layout-both-columns.tpl', null, 'layouts/layout-left-column.tpl', 0, 31536000, array(), 2, false, null, null)
in smarty_internal_runtime_inheritance.php line 125
at Smarty_Internal_Runtime_Inheritance->endChild(object(SmartyDevTemplate), 'layouts/layout-both-columns.tpl')
in f59585abba9ae60d008eabef2170d328bf83d5bc_2.file.layout-left-column.tpl.php line 33
at content_5f4ac05574faf9_53073824(object(SmartyDevTemplate))
in smarty_template_resource_base.php line 123
at Smarty_Template_Resource_Base->getRenderedTemplateCode(object(SmartyDevTemplate))
in smarty_template_compiled.php line 114
at Smarty_Template_Compiled->render(object(SmartyDevTemplate))
in smarty_internal_template.php line 216
at Smarty_Internal_Template->render()
in smarty_internal_template.php line 385
at Smarty_Internal_Template->_subTemplateRender('layouts/layout-left-column.tpl', null, 'layouts/layout-left-column.tpl', 0, 31536000, array(), 2, false, null, null)
in smarty_internal_runtime_inheritance.php line 125
at Smarty_Internal_Runtime_Inheritance->endChild(object(SmartyDevTemplate), 'layouts/layout-left-column.tpl')
in 286e6bda4f50276a3191690073954c4eeb3724a2_2.file.checkout.tpl.php line 35
at content_5f4ac05574b639_24525461(object(SmartyDevTemplate))
in smarty_template_resource_base.php line 123
at Smarty_Template_Resource_Base->getRenderedTemplateCode(object(SmartyDevTemplate))
in smarty_template_compiled.php line 114
at Smarty_Template_Compiled->render(object(SmartyDevTemplate))
in smarty_internal_template.php line 216
at Smarty_Internal_Template->render(false, 0)
in smarty_internal_templatebase.php line 232
at Smarty_Internal_TemplateBase->_execute(object(SmartyDevTemplate), null, 'layouts/layout-left-column.tpl', null, 0)
in smarty_internal_templatebase.php line 116
at Smarty_Internal_TemplateBase->fetch('checkout/checkout.tpl', null, 'layouts/layout-left-column.tpl', null, false, true, false)
in SmartyDev.php line 40
at SmartyDev->fetch('checkout/checkout.tpl', null, 'layouts/layout-left-column.tpl')
in FrontController.php line 683
at FrontControllerCore->smartyOutputContent('checkout/checkout.tpl')
in FrontController.php line 667
at FrontControllerCore->display()
in Controller.php line 312
at ControllerCore->run()
in Dispatcher.php line 515
at DispatcherCore->dispatch()
in index.php line 28