Product variations ‘out of stock’

I am with the same problem but no one in the forum can help.

That’s a serious problem ?? I’ve a lot of variable products!

Which version of WooCommerce are you using currently? Can you check that you are running MySQL 5.6 or higher and PHP 7.0 or higher?
Could you share your System report with us? You can find it in your dashboard under WooCommerce >> Status. This can help us to guide you to the next step in troubleshooting.

### WordPress Environment ###

Home URL: https://www.xyz.com
Site URL: https://www.xyz.com
WC Version: 3.2.4
Log Directory Writable: ?
WP Version: 4.8.3
WP Multisite: –
WP Memory Limit: 256 MB
WP Debug Mode: –
WP Cron: ?
Language: it_IT

### Server Environment ###

Server Info: Apache
PHP Version: 7.0.25
PHP Post Max Size: 55 MB
PHP Time Limit: 300
PHP Max Input Vars: 3000
cURL Version: 7.55.1
OpenSSL/1.0.1e

SUHOSIN Installed: –
MySQL Version: 5.6.37
Max Upload Size: 50 MB
Default Timezone is UTC: ?
fsockopen/cURL: ?
SoapClient: ?
DOMDocument: ?
GZip: ?
Multibyte String: ?
Remote Post: ?
Remote Get: ?

### Database ###

WC Database Version: 3.2.4
WC Database Prefix: wp_
Total Database Size: 135.33MB
Database Data Size: 85.15MB
Database Index Size: 50.18MB
wp_woocommerce_sessions: Data: 23.30MB + Index: 0.56MB
wp_woocommerce_api_keys: Data: 0.00MB + Index: 0.00MB
wp_woocommerce_attribute_taxonomies: Data: 0.00MB + Index: 0.01MB
wp_woocommerce_downloadable_product_permissions: Data: 0.00MB + Index: 0.00MB
wp_woocommerce_order_items: Data: 1.19MB + Index: 0.66MB
wp_woocommerce_order_itemmeta: Data: 6.55MB + Index: 6.00MB
wp_woocommerce_tax_rates: Data: 0.00MB + Index: 0.01MB
wp_woocommerce_tax_rate_locations: Data: 0.00MB + Index: 0.00MB
wp_woocommerce_shipping_zones: Data: 0.00MB + Index: 0.00MB
wp_woocommerce_shipping_zone_locations: Data: 0.00MB + Index: 0.00MB
wp_woocommerce_shipping_zone_methods: Data: 0.00MB + Index: 0.00MB
wp_woocommerce_payment_tokens: Data: 0.00MB + Index: 0.00MB
wp_woocommerce_payment_tokenmeta: Data: 0.00MB + Index: 0.00MB
wp_woocommerce_log: Data: 0.00MB + Index: 0.00MB
wp_ac_abandoned_cart_history_lite: Data: 1.52MB + Index: 0.00MB
wp_ac_email_templates_lite: Data: 0.02MB + Index: 0.00MB
wp_ac_guest_abandoned_cart_history_lite: Data: 0.05MB + Index: 0.00MB
wp_ac_sent_history_lite: Data: 0.08MB + Index: 0.00MB
wp_be_product_alert_sessions: Data: 0.00MB + Index: 0.00MB
wp_be_product_alert_signups: Data: 0.00MB + Index: 0.00MB
wp_commentmeta: Data: 0.31MB + Index: 0.17MB
wp_comments: Data: 4.52MB + Index: 1.94MB
wp_cp_feeds: Data: 0.00MB + Index: 0.00MB
wp_eg_grids: Data: 0.01MB + Index: 0.00MB
wp_eg_item_elements: Data: 0.00MB + Index: 0.00MB
wp_eg_item_skins: Data: 0.57MB + Index: 0.01MB
wp_eg_navigation_skins: Data: 0.05MB + Index: 0.00MB
wp_ewwwio_images: Data: 1.58MB + Index: 1.65MB
wp_faq_termmeta: Data: 0.00MB + Index: 0.00MB
wp_links: Data: 0.00MB + Index: 0.00MB
wp_manufacturer: Data: 0.00MB + Index: 0.00MB
wp_options: Data: 6.52MB + Index: 1.67MB
wp_postmeta: Data: 24.56MB + Index: 32.11MB
wp_posts: Data: 5.52MB + Index: 1.34MB
wp_revslider_css: Data: 0.13MB + Index: 0.01MB
wp_revslider_layer_animations: Data: 0.00MB + Index: 0.00MB
wp_revslider_navigations: Data: 0.00MB + Index: 0.00MB
wp_revslider_settings: Data: 0.00MB + Index: 0.00MB
wp_revslider_sliders: Data: 0.01MB + Index: 0.00MB
wp_revslider_slides: Data: 0.98MB + Index: 0.00MB
wp_revslider_static_slides: Data: 0.00MB + Index: 0.00MB
wp_say_what_strings: Data: 0.00MB + Index: 0.00MB
wp_termmeta: Data: 0.07MB + Index: 0.06MB
wp_terms: Data: 0.03MB + Index: 0.05MB
wp_term_relationships: Data: 0.27MB + Index: 0.58MB
wp_term_taxonomy: Data: 0.05MB + Index: 0.04MB
wp_usermeta: Data: 5.89MB + Index: 2.78MB
wp_users: Data: 0.27MB + Index: 0.27MB
wp_vtprd_purchase_log: Data: 0.00MB + Index: 0.00MB
wp_vtprd_purchase_log_product: Data: 0.00MB + Index: 0.00MB
wp_vtprd_purchase_log_product_rule: Data: 0.00MB + Index: 0.00MB
wp_wcpdf_invoice_number: Data: 0.00MB + Index: 0.00MB
wp_woocommerce_gpf_google_taxonomy: Data: 0.86MB + Index: 0.00MB
wp_woocommerce_shipping_zone_shipping_methods: Data: 0.00MB + Index: 0.00MB
wp_wsluserscontacts: Data: 0.00MB + Index: 0.00MB
wp_wslusersprofiles: Data: 0.08MB + Index: 0.01MB
wp_yith_wcwl: Data: 0.10MB + Index: 0.19MB
wp_yith_wcwl_lists: Data: 0.02MB + Index: 0.04MB
wp_yoast_seo_links: Data: 0.03MB + Index: 0.01MB
wp_yoast_seo_meta: Data: 0.01MB + Index: 0.01MB
wp_ywrr_email_blocklist: Data: 0.00MB + Index: 0.00MB
wp_ywrr_email_schedule: Data: 0.00MB + Index: 0.00MB

### Post Type Counts ###

attachment: 1884
contact-form: 2
easingslider: 1
faq: 8
gema75_wc_badge: 1
gift_card: 3
logo: 8
mc4wp-form: 1
ml-slider: 9
nav_menu_item: 293
newsletter: 2
page: 71
portfolios: 2
post: 11
po_interior_desi: 8
po_lookbook_fash: 5
product: 1076
product_tabpage: 1
product_variation: 570
revision: 122
shop_coupon: 56
shop_order: 2498
shop_order_refund: 5
shop_webhook: 1
sliders: 7
sl_grid_slider: 10
sl_smalti_avril: 2
teams: 1
team_team: 4
testimonial: 6
wpcf7_contact_form: 1
yith-wcbm-badge: 2
ywar_reviews: 11
ywcm_message: 2
ywrac_cart: 4

### Security ###

Secure connection (HTTPS): ?Il tuo negozio non utilizza HTTPS. Scopri di più su HTTPS e certificati SSL .
Hide errors from visitors: ?

### Active Plugins (31) ###

Akismet Anti-Spam: by Automattic – 4.0.1
Contact Form 7: by Takayuki Miyoshi – 4.9.1
Google Analytics for WordPress by MonsterInsights: by MonsterInsights – 6.2.6
Instagram Feed: by Smash Balloon – 1.5
WPBakery Page Builder: by Michael M - WPBakery.com – 5.4.2
MailChimp per WordPress: by ibericode – 4.1.11
MetaSlider: by Team Updraft – 3.6.5
Really Simple CAPTCHA: by Takayuki Miyoshi – 2.0.1
Regenerate Thumbnails: by Alex Mills (Viper007Bond) – 2.3.1
Revolution Slider: by ThemePunch – 5.4.6.2
Simple Facebook Page Plugin: by Dylan Ryan – 1.5.0
WooCommerce Product Feed: by WebAppick – 2.1.24 – Not tested with the active version of WooCommerce
Abandoned Cart Lite for WooCommerce: by Tyche Softwares – 4.4 – Not tested with the active version of WooCommerce
WooCommerce Breadcrumb Permalinks: by Bryce Adams – 1.1.0 – Not tested with the active version of WooCommerce
Booster for WooCommerce: by Algoritmika Ltd – 3.2.2 – Not tested with the active version of WooCommerce
WooCommerce PDF Invoices & Packing Slips: by Ewout Fernhout – 2.0.15 – Not tested with the active version of WooCommerce
WooCommerce PDF Invoices & Packing Slips Premium Templates: by Ewout Fernhout – 2.2.0 – Not tested with the active version of WooCommerce
Woocommerce Request a Review: by Code Ninjas – 1.0 – Not tested with the active version of WooCommerce
WooCommerce Smart Coupons: by WooThemes – 3.0.12 – 3.3.8 è disponibile – Not tested with the active version of WooCommerce
WooCommerce Table Rate Shipping: by Bolder Elements – 3.6.5 – Not tested with the active version of WooCommerce
WooCommerce Variation Swatches and Photos: by Lucas Stark – 1.6.6 – 3.0.4 è disponibile – Not tested with the active version of WooCommerce
WooCommerce: by Automattic – 3.2.4
Yoast SEO: by Team Yoast – 5.8
WordPress Social Login: by Miled – 2.3.3
YITH WooCommerce Ajax Product Filter: by YITHEMES – 3.4.6 – Not tested with the active version of WooCommerce
YITH WooCommerce Ajax Search: by YITHEMES – 1.5.4 – Not tested with the active version of WooCommerce
YITH WooCommerce Badge Management: by YITHEMES – 1.3.6 – Not tested with the active version of WooCommerce
YITH WooCommerce Cart Messages: by YITHEMES – 1.2.2 – Not tested with the active version of WooCommerce
YITH WooCommerce Waiting List: by YITHEMES – 1.1.2 – Not tested with the active version of WooCommerce
YITH WooCommerce Wishlist: by YITHEMES – 2.1.2 – Not tested with the active version of WooCommerce
Zendesk Chat Widget: by Zopim – 1.4.11

### Settings ###

API Enabled: ?
Force SSL: –
Currency: EUR (€)
Currency Position: left
Thousand Separator: .
Decimal Separator: ,
Number of Decimals: 2
Taxonomies: Product Types: external (external)
gift-card (gift-card)
grouped (grouped)
simple (simple)
variable (variable)

Taxonomies: Product Visibility: exclude-from-catalog (exclude-from-catalog)
exclude-from-search (exclude-from-search)
featured (featured)
outofstock (outofstock)
rated-1 (rated-1)
rated-2 (rated-2)
rated-3 (rated-3)
rated-4 (rated-4)
rated-5 (rated-5)

### WC Pages ###

Shop base: #4 - /negozio/
Carrello: #5 - /carrello/
Cassa: #6 - /checkout/
Il mio account: #7 - /il-mio-account/
Termini e condizioni: #1518 - /termini-condizioni-di-vendita/

### Theme ###

Name: Nielsen Child
Version: 1.4.6
Author URL: https://yithemes.com/
Child Theme: ?
Parent Theme Name: Nielsen
Parent Theme Version: 1.4.6
Parent Theme Author URL: https://yithemes.com/
WooCommerce Support: ?

### Templates ###

Overrides: nielsen/woocommerce/archive-product.php
nielsen/woocommerce/cart/cart-empty.php
nielsen/woocommerce/cart/cart-shipping.php
nielsen/woocommerce/cart/cart-totals.php
nielsen/woocommerce/cart/cart.php
nielsen/woocommerce/cart/cross-sells.php
nielsen/woocommerce/cart/mini-cart.php
nielsen/woocommerce/cart/shipping-calculator.php
nielsen/woocommerce/checkout/form-checkout.php
nielsen/woocommerce/checkout/form-coupon.php
nielsen/woocommerce/checkout/form-login.php
nielsen/woocommerce/checkout/review-order.php
nielsen/woocommerce/content-product.php
nielsen/woocommerce/content-product_cat.php
nielsen/woocommerce/content-single-product.php
nielsen/woocommerce/content-widget-product.php
nielsen/woocommerce/global/wrapper-end.php
nielsen/woocommerce/global/wrapper-start.php
nielsen/woocommerce/loop/add-to-cart.php
nielsen/woocommerce/loop/loop-end.php
nielsen/woocommerce/loop/loop-start.php
nielsen/woocommerce/loop/sale-flash.php
nielsen/woocommerce/myaccount/my-downloads.php
nielsen/woocommerce/myaccount/navigation.php
nielsen/woocommerce/single-product/add-to-cart/external.php
nielsen/woocommerce/single-product/add-to-cart/simple.php
nielsen/woocommerce/single-product/add-to-cart/variable.php
nielsen/woocommerce/single-product/product-image.php
nielsen/woocommerce/single-product/rating.php
nielsen/woocommerce/single-product/related.php
nielsen/woocommerce/single-product/sale-flash.php
nielsen/woocommerce/single-product/up-sells.php
nielsen/woocommerce/single-product-reviews.php

You have a couple of plugins that are out of date (and might not work correctly with WooCommerce 3.x). That’s why I suspect that one of those plugins conflicts with the normal functionalities. If updating those plugins does not solve the problem, can you follow the step in this troubleshooting guide and share the plugin that seems to be responsible for this behaviour?