Hello,
https://xstore.helpscoutdocs.com/article/60-xstore-theme-requirements – go to Dashboard of XStore to see your current values, for example – https://prnt.sc/qgqebc Your hosting provider should be able to help you increase required values.
If all media items can’t be installed automatically, we can help you and upload some missing images manually. Please provide us with temporary wp-admin access.
Make sure that you have the latest version of the XStore theme (6.2.5).
Regards