Not working

At the beginning, I press START to create the new staging site, but it returns an error. Even if in the settings I say to disable ALL the plugins.

The error I get is this:

Fatal Error: This should not happen but is most often caused by other plugins. Try first the option "Optimizer" in WP Staging->Settings and try again. If this does not help, enable wordpress debug mode to find out which plugin is causing this: 503 Service Unavailable

In debug mode, the only relevant message I see is this one:

disk_free_space(): Value too large for defined data type in /home/youtubeaml/www/wp-content/plugins/wp-staging/includes/template-functions.php on line 1711
 Type: PHP Warning
 Line: 1711
 File: /home/youtubeaml/www/wp-content/plugins/wp-staging/includes/template-functions.php

Below I’ve pasted the system info (if I press the download button I get a page not found error).

### Begin System Info ###

-- Site Info

Site URL:                 http://www.youtubeaddicted.com
Home URL:                 http://www.youtubeaddicted.com
Multisite:                No

-- User Browser

Platform:                 Apple
Browser Name:             Chrome
Browser Version:          45.0.2454.85
User Agent String:        Mozilla/5.0 (Macintosh; Intel Ma
			  c OS X 10_10_5) AppleWebKit/537.
                          36 (KHTML, like Gecko) Chrome/45
                          .0.2454.85 Safari/537.36

-- WordPress Configuration

Version:                  4.3
Language:                 en_US
Permalink Structure:      /%postname%/
Active Theme:             Focus Premium Child 1.0.1429107227
Show On Front:            page
Page On Front:            Youtubeaddicted (#118)
Page For Posts:           Unset
Remote Post:              wp_remote_post() works
Table Prefix:             Length: 7   Status: Acceptable
WP_DEBUG:                 Enabled
Memory Limit:             40M
Registered Post Stati:    publish, future, draft, pending, private, trash, auto-draft, inherit

-- WPSTG Configuration

Version:                  0.9.5
Upgraded From:            None

-- WordPress Active Plugins

Automatic Video Posts: 4.9.5
BackUpWordPress: 3.2.7
Child Theme Configurator: 1.7.6.1
Contact Form 7: 4.2.2
Custom Content Shortcode: 2.9.0
Debug Bar: 0.8.2
Debug Bar Actions and Filters Addon: 1.4.1
Debug Bar Slow Actions: 0.8.3
Debug This: 0.4
Disable New User Notifications: 1.0.1
Disable Toolbar: 1.0
Easy Theme and Plugin Upgrades: 1.0.4
Export Users to CSV: 1.0.0
Focus Video Plugin: 1.0
Google Analytics Dashboard for WP: 4.8.2
Like Dislike Counter Pro: 3.1.0
MailMunch - Increase your Email Subscribers by over 500%: 2.0.1
Related Posts By Taxonomy: 2.0.1
Remove Author Pages: 0.2
Share Buttons by AddToAny: 1.6.5
Shortcode Exec PHP: 1.52
Simple Share Buttons Adder: 6.0.4
Social Media Feather: 1.7.8
Theme My Login: 6.3.12
Ultimate Member: 1.3.23
WP-FB-AutoConnect: 4.1.1
WP Log Viewer: 0.12.5
WP Staging - Create a staging clone site for testing & developing: 0.9.5
Yoast SEO: 2.3.4

-- WordPress Inactive Plugins

-- Webserver Configuration

PHP Version:              5.5.22
MySQL Version:            5.1.73
Webserver Info:           Apache

-- PHP Configuration

Safe Mode:                Disabled
Memory Limit:             512M
Upload Max Size:          64M
Post Max Size:            64M
Upload Max Filesize:      64M
Time Limit:               0
Max Input Vars:           16000
Display Errors:           N/A

-- PHP Extensions

cURL:                     Supported
fsockopen:                Supported
SOAP Client:              Installed
Suhosin:                  Not Installed

### End System Info ###

https://ww.wp.xz.cn/plugins/wp-staging/