I changed the PHP version on the hosting and the site crashed, what should I do?

Question

WordPress

Hello, please help me, I didn’t think and updated the php version through Beget hosting, I first changed the php version, and only then I saved the backup copy in the UpdraftPlus - Backup / Restore plugin and now I can’t enter the WP admin panel and the site itself is not displayed anywhere. I go through the domain and it says (A critical error has occurred on the site.)

The php version was 5.6, I changed it to the latest 7.4, then to 7 and then to 5.6, and more than a day has passed, the site does not work at all.

php_errors log file appeared in hosting file manager

Answer 1

When moving from 5.6 to the latest version, many standard functions and methods simply stopped working, which were replaced by something else. Naturally, you need to look at what swears and use Google to replace parts of the code.

Answer 2

1 put the version back.
2 find where backups are made on the hosting restore yesterday. Both files and databases

Answer 3

https://wordpress.org/support/article/debugging-in...
You can write debug constants in wp-config.php

Answer 4

Works - do not touch.
Or touch, but on a test site.
1. Return the version to 5.6;
2. Restore files from the hoster's / own backup;
3. Throw off, finally, the text of the error. Troubleshooting without it is like pointing your finger at the sky.
Compatibility between versions 5.* and 7.* is disgusting.

Answer 5

Change it back

Answer 6

Try to update WP to the latest version (if it has not been updated for a long time) and then install PHP, but again, work is not guaranteed, because you need to see what the problems are (and why do you need it at all? Besides being "cool and fast"?) If the blog is old, before updating php, you need to do a "bunch" of work to update it (and transfer all crutches) to the new version

Answer 7

Drop the link to the site! You need to look for mistakes and fix them!