Import error..

I was trying to install the importer plugin few times but didnt install it and redirected to current theme home page saying page not found..

But after keep trying managed to install the plugin..

then I was trying to import the dummy content for the theme and it comes up to select user and tick to download all the images button.. and then after while it redirects to again page not found thing on the existing theme.

I havent encountered this strange thing ever.. can some one please advice me what to do?

Is that a problem with server?

I tried with the other server we have it works fine in there.. But only problem is I have to install this in this particular server..

Thanks

https://wordpress.org/plugins/wordpress-importer/