Unable to import all posts from previous blog to a new one

Hello, I am giving a facelift to a previous blog and I wanted to transfer the posts from that blog to the new one. I followed all the methods and upon getting the error to change in php.ini the upload size and max post size and that got rid of the error but now I am getting a blank screen. Literally, that is it! The upload isn’t successful either. I changed the URL in import.php to say import.php instead of admin.php and that didn’t work either!
The file I have for upload is 8.01MB and max upload size is 128MB for everything in php.ini

Here is my server log :`

[Tue Dec 29 11:56:21 2015] [error] [client 115.254.0.9] PHP Fatal error:  Class 'DOMDocument' not found in /home/multiplestreammktg/docs/dev/msmtest/blog/wp-content/plugins/wordpress-importer/parsers.php on line 61, referer: https://www.multiplestreammktg.com/dev/msmtest/blog/wp-admin/import.php?import=wordpress
[Tue Dec 29 12:01:22 2015] [error] [client 207.46.13.121] File does not exist: /home/multiplestreammktg/docs/robots.txt
[Tue Dec 29 12:08:20 2015] [error] [client 94.228.34.251] File does not exist: /home/multiplestreammktg/docs/robots.txt
[Tue Dec 29 12:11:03 2015] [error] [client 157.55.39.92] File does not exist: /home/multiplestreammktg/docs/robots.txt
[Tue Dec 29 12:14:04 2015] [error] [client 115.254.0.9] PHP Fatal error:  Class 'DOMDocument' not found in /home/multiplestreammktg/docs/dev/msmtest/blog/wp-content/plugins/wordpress-importer/parsers.php on line 61, referer: https://www.multiplestreammktg.com/dev/msmtest/blog/wp-admin/admin.php?import=wordpress
[Tue Dec 29 12:17:11 2015] [error] [client 40.77.167.24] File does not exist: /home/multiplestreammktg/docs/robots.txt
[Tue Dec 29 12:24:47 2015] [error] [client 8.37.70.234] File does not exist: /home/multiplestreammktg/docs/robots.txt
[Tue Dec 29 12:25:49 2015] [error] [client 157.55.39.28] File does not exist: /home/multiplestreammktg/docs/robots.txt
[Tue Dec 29 12:26:58 2015] [error] [client 176.97.116.136] File does not exist: /home/multiplestreammktg/docs/wp-content/themes/kernel-theme, referer: https://multiplestreammedia.com/wp-content/themes/kernel-theme/functions/upload-handler.php
[Tue Dec 29 12:38:11 2015] [error] [client 46.118.155.216] File does not exist: /home/multiplestreammktg/docs/robots.txt
[Tue Dec 29 12:38:17 2015] [error] [client 46.118.155.216] File does not exist: /home/multiplestreammktg/docs/wp-content/plugins/formcraft
[Tue Dec 29 12:38:21 2015] [error] [client 46.118.155.216] File does not exist: /home/multiplestreammktg/docs/wp-content/plugins/revslider
[Tue Dec 29 12:38:23 2015] [error] [client 46.118.155.216] File does not exist: /home/multiplestreammktg/docs/wp-content/uploads/wpallimport
[Tue Dec 29 12:41:25 2015] [error] [client 157.55.39.92] File does not exist: /home/multiplestreammktg/docs/robots.txt
[Tue Dec 29 12:46:33 2015] [error] [client 74.125.93.113] File does not exist: /home/multiplestreammktg/docs/feed
[Tue Dec 29 12:46:38 2015] [error] [client 157.55.39.28] File does not exist: /home/multiplestreammktg/docs/robots.txt
[Tue Dec 29 12:46:38 2015] [error] [client 115.254.0.9] PHP Fatal error:  Class 'DOMDocument' not found in /home/multiplestreammktg/docs/dev/msmtest/blog/wp-content/plugins/wordpress-importer/parsers.php on line 61, referer: https://www.multiplestreammktg.com/dev/msmtest/blog/wp-admin/admin.php?import=wordpress
[Tue Dec 29 12:51:37 2015] [error] [client 107.170.114.242] File does not exist: /home/multiplestreammktg/docs/robots.txt
[Tue Dec 29 12:51:38 2015] [error] [client 107.170.114.242] File does not exist: /home/multiplestreammktg/docs/robots.txt
[Tue Dec 29 12:52:07 2015] [error] [client 115.254.0.9] PHP Fatal error:  Class 'DOMDocument' not found in /home/multiplestreammktg/docs/dev/msmtest/blog/wp-content/plugins/wordpress-importer/parsers.php on line 61, referer: https://www.multiplestreammktg.com/dev/msmtest/blog/wp-admin/import.php?import=wordpress