vertical line in the product detail

Hi perutec
In your case, you should update to the latest theme version. it's version 3.0.8 and let me know your results.
Regards

can you give me information on how I should update the subject please, thank you

here are some steps
Step 1: Backup your site( Include codes + Database)
Step 2: From the dashboard>>Appearance>>Theme, you need to activate the default template( Ex; Twenty Seventeen theme)
( you can refer this document, it's the same http://test.kutethemes.net/koolshop_doc/#mazanoupdate)
Step 3: Click on KuteShop and then click Delete( look down in the right). NOTE: DO NOT delete the KuteShop-Child
Step 4: Return the dashboard choose Plugins then deactive the KuteShop Toolkit, Slider Revolution, WPBakery Visual Composer and delete them.
Step 5: Return the Appearance menus choose Theme>>Add New>>choose your latest theme version>>Install
Step 6: Return the Plugins menus>>New>>and choose the Kuteshop Toolkit (Slider Revolution, WPBakery Visual Composer plugins are the same)>>Install>>and activate them.
Please do it and let me know.