Minor issue on the update. After successful update thru CLI, site and pages load correctly, but CP asset thumbnails are blank/empty/not rendering. This persists until the CP crashes on the browsing assets page. Replicated in all browsers but seems like a issue with the change I made in yaml_parser: symfony to system.yaml.
Clearing Stache, chache etc. didnt help yet. Crashes my local valet nginx setup. Anyone know if I need get my YAML in spec with 1.2 symfony? Any ideas or tips?