CEPHtmlEngine keeps macOS awake
CEPHtmlEngine erroneously keeps macOS awake by setting PreventUserIdleSystemSleep
See details below, CEPHtmlEngine is unnecessarily keeping macOS awake using the power management API and asserting PreventUserIdleSystemSleep, on this device it has been asserting and renewing its assertion for 170 hours.
This presents a massive physical security risk to enterprise customers as it defeats IT controlled sleep/screensaver/walkaway preferences to lock the computer.
nick@Nicholass-MacBook-Pro ~ % pmset -g assertions
2025-04-29 17:49:04 -0400
Assertion status system-wide:
BackgroundTask 0
ApplePushServiceTask 0
UserIsActive 1
PreventUserIdleDisplaySleep 1
PreventSystemSleep 0
ExternalMedia 0
PreventUserIdleSystemSleep 1
NetworkClientActive 0
Listed by owning process:
pid 515(powerd): [0x00071b6c00019d4e] 00:04:13 PreventUserIdleSystemSleep named: "Powerd - Prevent sleep while display is on"
pid 54064(CEPHtmlEngine): [0x000166200005a544] 170:43:06 NoDisplaySleepAssertion named: "Video Wake Lock"
pid 962(WindowServer): [0x00071c6200099e21] 00:00:00 UserIsActive named: "com.apple.iohideventsystem.queue.tickle serviceID:10005e0bf service:AppleHIDKeyboardEventDriverV2 product:Apple Internal Keyboard / Trackpad eventType:3"
Timeout will fire in 120 secs Action=TimeoutActionRelease
No kernel assertions.
Nick McDonald
shared this idea
The issue is being tracked and is awaiting the fix by CEP team
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RV
commented
Dear Adobe Support Team,
I am writing to report an ongoing issue affecting macOS systems, specifically related to the background process CEPHtmlEngine, which is part of Adobe Creative Cloud applications.
# Issue Overview
On macOS, CEPHtmlEngine consistently prevents the system from entering sleep mode, even after all Adobe applications have been closed. This results in increased battery drain, unnecessary energy consumption, and disruption to system workflows.
The problem has been observed and confirmed via the Terminal command:
pmset -g assertions
This outputs:PreventUserIdleSystemSleep 1
pid [XXXX] CEPHtmlEngine# Impact
Battery Drain: On laptops, the inability to sleep drains the battery and impacts mobility.
Thermal Load: In some cases, CEPHtmlEngine causes higher CPU usage.
Workflow Disruption: Automated sleep schedules or energy-saving setups are affected.
Security Concerns: Background processes persisting post-app closure may conflict with IT policies.# Request for Adobe
Please investigate why CEPHtmlEngine is blocking system sleep persistently.
Can Adobe provide an option in preferences or an update to control or disable this behavior?
Will future updates ensure CEPHtmlEngine respects macOS system sleep policies?# Temporary Workaround (User-Side)
At present, users are forced to terminate the process manually via:
killall CEPHtmlEngine
However, this is not ideal or practical for most usersI kindly request that this issue be escalated to the appropriate development team for review and resolution.
Thank you for your attention,
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Beardmancer
commented
Still happening for me on macOS, Illustrator 29.4. In Activity Monitor, under the Energy tab, expanding the entry for Illustrator shows that CEPHtmlEngine is preventing sleep. It keeps my monitors on indefinitely until I quit the app.
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Peter Hildebrandt
commented
This problem remains. Is anyone else having problems with the sleep because of illustrator?
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Peter Hildebrandt
commented
Upon further checking, the problem has not been resolved. It did it again with 28.71.
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Peter Hildebrandt
commented
This appears to have been fixed in 28.7.1.
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Peter Hildebrandt
commented
After editing the first text box in an Illustrator document, my computer will neither blank the screen nor go to sleep until Illustrator is closed. The problem started when I installed version 28.6. I am running Windows 10.
The POWERCFG utility in Windows indicates that the offending module is CEPHtmlEngine\CEPHtmlEngine.exe. Don't know if that's helpful. See the screen capture below.