Hello the All-in-one WP Migration plugin developers changed the way they limit FILE UPLOAD SIZE. This causes some limitations on some servers. We're sorry there's not much we can do about this, but help solve it quickly.
If it happens that when you try to upload your .wpress file the uploads stops at a certain % without going any further.
You need to download and install the the All-in-one WP Migration EXTENSION PLUGIN.
Go to https://import.wp-migration.com/ and on that page you will click the big blue "Download" button under the "Basic" column.
Save the plugin on your desktop and then install it on your WordPress website as you do with any plugins. DO NOT deactivate the All-in-one WP Migration installed, just install the new one, both must activated.
Once the plugin extension is installed, just proceed again from there with the installation and Upload your .wpress file again. Everything should work very fine from there.
For more information check out the File Extension User Guide.