Two Kirby sites are now throwing errors

Woke this morning to find two Kirby sites now refusing to work because of this error, amongst others:

[24-Feb-2026 04:58:41 UTC] Error: Call to a member function root() on null in /home/xxxxxx/domains/dev.brendandawes.com/html/kirby/src/Cms/Media.php:146
Stack trace:
#0 /home/xxxxxx/domains/dev.brendandawes.com/html/kirby/src/Cms/Media.php(61): Kirby\Cms\Media::thumb()
#1 /home/xc4ki26cj9i0/domains/dev.brendandawes.com/html/kirby/config/routes.php(89): Kirby\Cms\Media::link()
#2 [internal function]: Kirby\Http\Route->{closure:{closure:/home/xxxxxx/domains/dev.brendandawes.com/html/kirby/config/routes.php:12}:84}()
#3 /home/xxxxxx/domains/dev.brendandawes.com/html/kirby/src/Http/Router.php(122): Closure->call()
#4 /home/xxxxxx/domains/dev.brendandawes.com/html/kirby/src/Cms/App.php(342): Kirby\Http\Router->call()
#5 /home/xxxxxx/domains/dev.brendandawes.com/html/kirby/src/Cms/App.php(1195): Kirby\Cms\App->call()
#6 /home/xxxxxx/domains/dev.brendandawes.com/html/index.php(5): Kirby\Cms\App->render()
#7 {main}

Site and content hasn’t changed. Hosting is using PHP 8.4 and I’m using Kirby 5. Everything fine yesterday, no updates in between.

Any ideas?

When visiting the site, I’m greeted with the fatal screen from Kirby telling me that the PHP version used is not supported. Kirby 8.4 is definitely supported by Kirby 5, but could you please verify the actually used PHP version to make sure that nothing has changed on the server overnight (maybe through the hosting company?)

Thanks. Will do a phpinfo and see what comes back. It is like they’ve downgraded php or something overnight.

Yep the server is now running version 7.3.33 even though the hosting dashboard is set to 8.4! Thanks for help, will investigate further