TYPO3 Core

After upgrading to Chrome 126.0.6478.62, the TYPO3 backend becomes unresponsive pretty quick.
The symptom is that loading certain backend modules (e.g. "List") and using the page tree seems to take forever, as the loading bar doesn't disappear after a few clicks.

After some investigation it has been revealed that this behavior happens with Chrome 126.0.6478.62, the previous version 126.0.6478.61 is not affected. The only change in this version is a partial revert of a SVG-related change, also see the related ticket.

After disabling the SvgSpriteIconProvider, the issue is gone:

diff --git a/typo3/sysext/core/Classes/Imaging/IconProvider/SvgSpriteIconProvider.php b/typo3/sysext/core/Classes/Imaging/IconProvider/SvgSpriteIconProvider.php
index c10c3b31f3..f48b7c6b31 100644
--- a/typo3/sysext/core/Classes/Imaging/IconProvider/SvgSpriteIconProvider.php
+++ b/typo3/sysext/core/Classes/Imaging/IconProvider/SvgSpriteIconProvider.php
@@ -38,7 +38,7 @@ class SvgSpriteIconProvider extends AbstractSvgIconProvider
         }

         $source = $options['sprite'];
-        return '<svg class="icon-color"><use xlink:href="' . htmlspecialchars($this->getPublicPath($source)) . '" /></svg>';
+        return '';
     }

     /**

We're either dealing with a edge-case here that is triggered by our SVG files, or we run into a Chromium regression – Firefox and Safari both are NOT affected.

It turns out that some promises get rejected after 30 seconds, which can be seen in the browser console. This is a special behavior of the @typo3/core/document-service module. The reason is that the iframe is stuck in the ready state interactive and never transitions to complete. This race condition is a follow-up error that will be handled with #104315: