One customer getting the error

[sahostking]

We strangely have 1 customer of ours getting this strange error:

Error: TypeError: Cannot access offset of type string on string in /whmcstemp/templates_c/493d42359642652f8f66241cb6128633e594b156_0.file.summary-table.tpl.php:413 Stack trace: #0 /public_html/vendor/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php(123): content_662b429ad78f89_28407453() #1 /public_html/vendor/smarty/smarty/libs/sysplugins/smarty_template_compiled.php(114): Smarty_Template_Resource_Base->getRenderedTemplateCode() #2 /public_html/vendor/smarty/smarty/libs/sysplugins/smarty_internal_template.php(216): Smarty_Template_Compiled->render() #3 /public_html/vendor/smarty/smarty/libs/sysplugins/smarty_internal_template.php(385): Smarty_Internal_Template->render() #4 /whmcstemp/templates_c/276510031b58c274a31bb22894ca0f3182a37657_0.file.viewcart.tpl.php(135): Smarty_Internal_Template->_subTemplateRender() #5 /public_html/vendor/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php(123): content_662b429acfa673_70116599() #6 /vendor/smarty/smarty/libs/sysplugins/smarty_template_compiled.php(114): Smarty_Template_Resource_Base->getRenderedTemplateCode() #7 /public_html/vendor/smarty/smarty/libs/sysplugins/smarty_internal_template.php(216): Smarty_Template_Compiled->render() #8 /public_html/vendor/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php(232): Smarty_Internal_Template->render() #9 /public_html/vendor/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php(116): Smarty_Internal_TemplateBase->_execute() #10/vendor/whmcs/whmcs-foundation/lib/Smarty.php(0): Smarty_Internal_TemplateBase->fetch() #11 /public_html/includes/clientareafunctions.php(0): WHMCS\Smarty->fetch() #12 /public_html/cart.php(0): outputClientArea() #13 {main}