Greetings, I mistakenly updated the php version via Beget hosting without taking a backup copy in UpdraftPlus-Backup/Restore plugin beforehand. I changed the php version from 7.4 to 8.1, then to 8, and reverted to 7.4, which resulted in my site becoming inaccessible and displaying a critical error message.

Furthermore, I observed that a php_errors log file was created in the hosting file manager. Can you kindly provide me with your support?

Once updated to the newest version, a lot of standard functions and methods have been substituted with different alternatives. It is crucial to recognize which functions have been affected and utilize Google to find the replaced ones to subsequently modify the code accordingly.

Wordpress.org/documentation/article/debugging-in-wordpress/ advises to register constants in wp-config.php for debugging purposes. It is crucial to exercise caution while doing so and make any modifications on a test site first. To debug, follow these steps:
1. Change the version back to 7.4;
2. Retrieve the files from the host's backup or your own backup;
3. Lastly, carefully examine the error text since debugging without it can be challenging. It's worth noting that compatibility between versions 7.* and 8.* is not great.

In addition to these steps, it is important to have a good understanding of the code in order to more efficiently debug any errors that may arise.

WordPress necessitates a PHP update for the reasons stated above; however, it operates seamlessly even on version 5.6.20 due to excellent backward compatibility. Whether or not to upgrade should be based on individual needs.

It is recommended to back up the site before upgrading so that it can be rolled back if necessary, and themes and plugins should be updated routinely to ensure uninterrupted functionality of the site. The PHP Compatibility Checker plugin can be used to discover compatibility issues, while problematic plugins and themes will need to be changed or reviewed by developers.

To guarantee proper functionality of updated plugins and themes, it is essential to choose developers with a good reputation. If the site malfunctions after updating PHP, plugins and themes may be the reason. Please be aware that WordPress support does not guarantee compatibility with the new version of PHP, therefore proper preparation is vital.

Updating PHP in WordPress can be accomplished by modifying the hosting settings on the control panel or by contacting technical support. For a more secure site, Joomla suggests upgrading to PHP 7.1 or later.

To upgrade to new PHP versions without any problems, your site should have at least Joomla 3.5. Contacting hosting support is typically the simplest method to update your PHP version, as they frequently do it for free and rapidly. Otherwise, updating can be done through .htaccess.

In summary, updating PHP can improve your website's security and functionality, but it's important to weigh the risks and take precautions such as backing up your site prior to any updates. Additionally, regularly updating themes and plugins will help ensure seamless functioning of your site.

It's essential to remain calm and approach the situation methodically. The creation of a php_errors log file indicates that there are errors logged within this file, and we can utilize this information to diagnose the specific issues affecting your website.
Initially, I recommend accessing the php_errors log file via your hosting file manager and reviewing the logged errors. The log will likely provide crucial insights into the nature of the critical error that is causing your site to be inaccessible. These details will guide us in determining the necessary steps to resolve the issue.

In addition, it's important to consider the compatibility of your website with the updated PHP versions. Sometimes, certain code or plugins may not be fully compatible with the latest PHP version, leading to critical errors. Understanding the potential source of the issue will assist in formulating an effective solution.

If you have access to your hosting control panel, you can also consider enabling error reporting to display errors directly on the website, which can aid in pinpointing the root cause of the critical error.

In the event that the critical error persists, rolling back to the previous PHP version where your website was fully functional may be a viable temporary solution. However, this should be accompanied by a thorough review of your website's code, plugins, and theme compatibility to ensure a smooth transition to an updated PHP version in the future.

Moving forward, regularly backing up your website files and database using a reliable backup solution like UpdraftPlus is imperative to safeguard against unforeseen issues such as this. Implementing a robust backup strategy is crucial in preserving the integrity of your website and ensuring quick recovery in case of unexpected events.
While encountering critical errors can be disheartening, it presents an opportunity to learn and reinforce the importance of proactive measures such as regular backups and cautious implementation of updates. Let's work together to analyze the logged errors, address compatibility concerns, and devise a sustainable solution to restore the functionality of your website.

Changing the PHP version on your web hosting can cause compatibility issues with your website's code. Please make sure the PHP versions match to avoid any issues. If you run into problems, consider checking for deprecated functions or deprecated syntax. Finally, thoroughly test your website after updating your PHP version to catch potential issues early.

It appears that a change in the PHP version has caused a compatibility issue with the website's code. Check the php_errors log file to identify the specific error that is causing the critical issue. Rolling back to a previous PHP version may resolve the issue. You may also need to debug your site's code and update it accordingly. If you are unsure how to proceed, please contact your hosting provider's support team.