Cannot access Cornerstone in any of my websites!

Support
#1

Please can you help as I cannot access any of my websites with Cornerstone… please advise solution asap as I have urgent work to complete…

Kind Regards
Roy

2 Likes
#2

I investigated the issue and fixed my dev sites. my team doesn’t’ have a downtime anymore, and I am sure Themeco’s update will be there soon to override the fix.

Claude Code:

Symptoms

All sites using Themeco Pro/Cornerstone suddenly show a critical error when launching the Cornerstone builder. No theme or plugin updates were applied — the issue appeared simultaneously across all sites.

Root Cause

Themeco’s legacy design cloud server ( demo.theme.co ) is currently returning 502 Bad Gateway . When Cornerstone loads the builder, it calls this server to fetch legacy template data. The 502 response is HTML, not JSON, so json_decode() returns null . On PHP 8.2+, passing null to array_filter() is a fatal error — crashing the builder.

The bug is in RemoteAssets.php — a missing null check that only surfaces when the external server is unavailable.

Fix

Edit this file in your Pro theme:

wp-content/themes/pro/cornerstone/includes/classes/Services/RemoteAssets.php

Find this code around line 186 :

$items = json_decode( wp_remote_retrieve_body( $request ), true );

$items = array_filter( $items, function( $item ) {

Add a null check between those two lines:

$items = json_decode( wp_remote_retrieve_body( $request ), true );

if (!is_array($items)) return [];

$items = array_filter( $items, function( $item ) {

Save the file. The builder will work immediately.

Notes

  • This only affects sites running PHP 8.2+ (where null→array type coercion is a fatal error)
  • The fix will be overwritten by the next Pro theme update, but by then Themeco will likely have patched this or their server will be back up
  • No templates are lost — the fix just skips the legacy template library while the server is down
5 Likes
Critical error when opening Cornerstone / Theme Options – RemoteAssets.php array_filter(null)
Critical error when opening Cornerstone / Theme Options – RemoteAssets.php array_filter(null)
Urgent: Fatal Error All sites Just now
Unable to edit via Cornerstone - Critical Error
#3
1 Like
#4

Thank you for the solution on Pro…

I have the same problem on x, where is the file to edit on x?

Regards

Roy

#5

In X, Cornerstone is a separate plugin.

You can find the correct file at
wp-content/plugins/cornerstone/includes/classes/Services/RemoteAssets.php

1 Like
#6

Big thanks… appreciate this!

#7

Thanks for the fix. Must be an April Fool’s joke from Themeco!

#8

We are having the same issue. Hopefully Themeco gets the server back up and running and issues a fix soon.

#9

A very big thank you!