onNetworkEvent resource://devtools/server/actors/resources/network-events.js:282
   #createNetworkEvent resource://devtools/shared/network-observer/NetworkObserver.sys.mjs:815
   <anonymous> resource://devtools/shared/network-observer/NetworkObserver.sys.mjs:407
   makeInfallible resource://devtools/shared/DevToolsInfaillibleUtils.sys.mjs:43

Many web pages now 'flash' when opened in FF (128.0.3 64bit W10). ALL graphics images turn on then off in synchrony. Text does not seem to be affected. Disabling HW acceleration has no effect. sample web page: https://www.cnbc.com/2024/08/01/eu-ai-act-goes-into-effect-heres-what-it-means-for-us-tech-firms.html This problem does NOT occur using Google Chrome. [One difference noted seems to be the TOP of the web page has an mp4 video advert. It displays in Chrome, but not in ffox] Partial Browser Console Report: Listener for event 'frame' did not return a promise. 2 event-emitter.js:248:23 Error while destroying front: inspector Error: Connection closed, pending request to server0.conn0.process46//inspectorActor71, type getWalker failed Request stack: request@resource://devtools/shared/protocol/Front.js:299:14 generateRequestMethods/</frontProto[name]@resource://devtools/shared/protocol/Front/FrontClassWithSpec.js:47:19 _getWalker@resource://devtools/client/fronts/inspector.js:84:30 initialize@resource://devtools/client/fronts/inspector.js:73:12 baseFrontClassDestroy resource://devtools/shared/protocol/Front.js:105 destroy resource://devtools/shared/protocol/Front.js:73 destroy resource://devtools/client/fronts/inspector.js:128 destroy resource://devtools/shared/protocol/Pool.js:211 baseFrontClassDestroy resource://devtools/shared/protocol/Front.js:109 _onTargetDestroyed resource://devtools/shared/commands/target/target-command.js:369 _destroyExistingTargetsOnTargetSwitching resource://devtools/shared/commands/target/target-command.js:275 _onTargetAvailable resource://devtools/shared/commands/target/target-command.js:205 _emit resource://devtools/shared/event-emitter.js:242 emit resource://devtools/shared/event-emitter.js:186 emit resource://devtools/shared/event-emitter.js:330 _onTargetAvailable resource://devtools/client/fronts/watcher.js:60 _emit resource://devtools/shared/event-emitter.js:242 emit resource://devtools/shared/event-emitter.js:186 emit resource://devtools/shared/event-emitter.js:330 onPacket resource://devtools/shared/protocol/Front.js:348 onPacket resource://devtools/client/devtools-client.js:458 send resource://devtools/shared/transport/local-transport.js:67 makeInfallible resource://devtools/shared/ThreadSafeDevToolsUtils.js:103 makeInfallible resource://devtools/shared/ThreadSafeDevToolsUtils.js:103 target-mixin.js:474:19 Failed to start [root-node] legacy listener for target null Error: Connection closed, pending request to server0.conn0.process46//inspectorActor71, type getWalker failed Request stack: request@resource://devtools/shared/protocol/Front.js:299:14 generateRequestMethods/</frontProto[name]@resource://devtools/shared/protocol/Front/FrontClassWithSpec.js:47:19 _getWalker@resource://devtools/client/fronts/inspector.js:84:30 initialize@resource://devtools/client/fronts/inspector.js:73:12 baseFrontClassDestroy resource://devtools/shared/protocol/Front.js:105 destroy resource://devtools/shared/protocol/Front.js:73 destroy resource://devtools/client/fronts/inspector.js:128 destroy resource://devtools/shared/protocol/Pool.js:211 baseFrontClassDestroy resource://devtools/shared/protocol/Front.js:109 _onTargetDestroyed resource://devtools/shared/commands/target/target-command.js:369 _destroyExistingTargetsOnTargetSwitching resource://devtools/shared/commands/target/target-command.js:275 _onTargetAvailable resource://devtools/shared/commands/target/target-command.js:205 _emit resource://devtools/shared/event-emitter.js:242 emit resource://devtools/shared/event-emitter.js:186 emit resource://devtools/shared/event-emitter.js:330 _onTargetAvailable resource://devtools/client/fronts/watcher.js:60 _emit resource://devtools/shared/event-emitter.js:242 emit resource://devtools/shared/event-emitter.js:186 emit resource://devtools/shared/event-emitter.js:330 onPacket resource://devtools/shared/protocol/Front.js:348 onPacket resource://devtools/client/devtools-client.js:458 send resource://devtools/shared/transport/local-transport.js:67 makeInfallible resource://devtools/shared/ThreadSafeDevToolsUtils.js:103 makeInfallible resource://devtools/shared/ThreadSafeDevToolsUtils.js:103 resource-command.js:1118:15 Unable to find target with innerWindowId:15032385981 watcher.js:188:13 Listener for event 'frame' did not return a promise. 5 event-emitter.js:248:23 Unable to find target with innerWindowId:15032386002 watcher.js:188:13 Unable to find target with innerWindowId:103079215105 watcher.js:188:13 Error: Got notified about channel 15032387338 more than once. onNetworkEvent resource://devtools/server/actors/resources/network-events.js:282 #createNetworkEvent resource://devtools/shared/network-observer/NetworkObserver.sys.mjs:815 <anonymous> resource://devtools/shared/network-observer/NetworkObserver.sys.mjs:407 makeInfallible resource://devtools/shared/DevToolsInfaillibleUtils.sys.mjs:43 DevToolsInfaillibleUtils.sys.mjs:22:13 Listener for event 'frame' did not return a promise. 6 event-emitter.js:248:23 Security state 0 has no known STATE_IS_* flags. DevToolsInfaillibleUtils.sys.mjs:22:13 Unable to find target with innerWindowId:15032386023