We think the problem is caused by php remote file open problem.
Please download the next steps.
1: Download "lorada-dummy-data.zip" from next link.
2: Please move downloaded file on wp-content/uploads/lorada_dummy folder.
If there is no "lorada_dummy" folder, please create new one.
3: Unzip the "lorada-dummy-data.zip" file and go to the admin->demo import page.
4: Please try again to import demo.
If you have the other problems, please let us know again.
Best Regards, C-Themes