Hello, @Techgaon,
The demo imports fine on your site there is no issue you can compare your page with our main demo link: https://xstore.8theme.com/elementor/demos/niche-market04/ the pages you mentioned are not included in the demo too and that is why these pages don’t import on your site as well.
There is no index.php in your site URL see here: https://silvermaharaja.com/contact-us/ This link is of your site and it appears to me like this: https://postimg.cc/TpGrgVYQ
Regarding the update theme issue, you are facing Please try the solution from this topic https://www.8theme.com/topic/the-package-could-not-be-installed-pclzip_err_bad_format-10-unable-to-find-2/#post-273465
Regards 8Themes Team.