Some users may face issues with Extension Activation after updating to MainWP v4.2. To resolve them, please follow the steps described here: Manage Add-ons - MainWP WordPress Management
After successful activation, try updating the plugins again.
Assuming that you have the Remember MainWP Main API Key box checked, please try deleting API Activation data.
Go to MainWP Dashboard > Settings > Tools and click the Delete extensions API Activation data button.
Then reactivate your Extensions Main API key.
If the issue persists, please try reinstalling the extensions. Go to WordPress Dashboard > Plugins page, deactivate and delete all MainWP extensions, and then Install them on MainWP Dashboard > Extensions page.
If that doesn’t help either, please open a private Help Desk ticket so we can collect some additional information & investigate further.
WordPress® is a registered trademark of the WordPress Foundation, and WooCommerce® is a registered trademark of WooCommerce, Inc. MainWP is an independent product and is not affiliated, associated, or endorsed by the WordPress Foundation, WooCommerce, Inc., or Automattic Inc., except where noted under the Jetpack® API and Trademark License Agreement. All product names, logos, and brands are property of their respective owners and are used for identification purposes only.