Mac Mojave Sys Prefs/Screensaver slows down, locks up

latest update 3 days ago mo improvement (security, supplemental, safari)

Sorry, did you mean *NO* improvement? Just want to make sure.

I guess we should all submit bug reports again. ugh.

"and the big ugly red thing is there." what u mean please (i dont have Big Sur maybe then i would know whats big and red)

Has anyone tried ArtSaver? http://www.cs.uni-bremen.de/~zach/software/ArtSaver/index.html

Any other alternatives to macOS photo screensaver?

What is "Shell"?

Same here just after latest Security and Safari update ..i updated about17th of July 2020

Loading screensaver makesmy Mac (Retina 5K, 27-inch, 2017) unresponsive for felt 2 minutes; even happens when i open preferences for screensaver; the issue occured with landscapes; switched now to flury .. seems to solve it in preferences it does not slow down .. hope it keeps in normal use.

(tried another user account on my computer .. the same happenes with landscapes

Same here. Any saver that uses a folder of images, be it Apple-created or user-created, will do it. I'm using Shell and it works.

Be sure to report this to Apple. They won't see your concern here. They WILL see problems reported using this Feedback link:

https://www.apple.com/feedback/macos.html

Historically, that method has been very effective.

Same issue noted here shortly after installing security update 2020-004 (July 2020) on both a MacBook Pro (early 2015) and a MacBook Air (early 2015) with the default collection folders. Thanks for the direct feedback link. Bug Report submitted.

UPDATE: Since the latest update to Safari 14 there seems to be an improvement, but i am not sure if this is randomly btw placebo-effect ;(wondering about what Safari got to do with the screensaver but as Safari is somehow part of the system software there may be some correlation)

Waiting for the screensaver when activates takes about 15 seconds. But still not ok because during this time the computer cannot be used.. The process stalls everything for at least 15 seconds. Happens when just looking for the screen-saver-settings in preferences and when screensaver is activated scheduled or by hot corners.

SOPRRY Problem NOT solved; it takes too long until my mac gets responsive when dealing with these photobased screensavers.

I have the same problem

Many bugs, including Permission problems from the 2020-005 SecUpd, the recent supplemental Update cured things for many, others need to reinstall Mojave.

Same here… Submitted a bug report. Though hope for help is minimal…

Yeah, not likely to help unless you take 200 million other with you to the complaint department.