Because site host PHP setting is not high enough. The images downloading will take long time, it always was timeout. I have imported 3-4 times manually until all images finish(refer this post – 2. “Import My Saved Data”,). But it only affect data importing.
The BM Pagebuilder was not activated before importing data, so the contact/about pages are empty. Please edit the page, you will see the modules. It is easy to replace as your own content. It is not necessary to import again.